Compact weather stations
Multiple measurements. One integrated platform.
MaxiMet combines meteorological measurements in a compact, integrated weather station, giving engineers a practical way to collect the environmental data their application needs without building a system from separate instruments.
Depending on configuration, MaxiMet measures wind speed and direction, temperature, humidity, pressure, precipitation and solar radiation, with selected models also providing compass, GPS, heating and derived meteorological parameters.
We aim to respond in one working day.

Rain and solar on board
Optical rainfall and solar radiation, by model
No moving parts
Ultrasonic wind, no cups or vanes
Temperature, humidity, pressure
Inside the louvred radiation shield
One cable, one output
RS232, RS422, RS485, SDI‑12, Modbus
- Several parameters, one instrumentUp to six measurements from a single mounting point
- Low-power operationEco Mode for solar and battery sites
- Heat-stress monitoringGMX552 measures WBGT and TWL for worker safety
- Sealed to IP66IP68 on MaxiMet Marine
The challenge
Weather rarely arrives as one measurement
A wind reading tells you what the air is doing. Temperature and humidity add context. Pressure changes the picture again. Add precipitation or solar radiation and the same installation can become a much more useful source of environmental information.
The engineering challenge is not simply to measure more. It is to gather the measurements that matter without turning the installation into a collection of separate instruments, cables, interfaces and maintenance requirements.
MaxiMet brings multiple measurements together in a compact platform, with different configurations allowing the station to be specified around the application rather than forcing every installation into the same specification.
Ultrasonic wind, no moving parts
No cups, bearings or vanes to wear out, lubricate or replace.
One unit, one cable
One output string into your logger, PLC or network.
IP66 across the range
IP68 on the marine GMX260 and GMX560.
Derived parameters built in
Dew point, wind chill, air density, true wind and WMO averages.
Choose your MaxiMet
Start with the measurements, not the model number
Every MaxiMet is the same instrument with a different measurement set. Tick what you need and the range narrows to the models that measure all of it.

GMX200
Wind only.

GMX240
Wind and rainfall, with no temperature, humidity or pressure.

GMX260
Wind with a 6-axis compass for moving platforms. IP66 and IP68.

GMX300
Temperature, humidity and pressure, with no wind.

GMX301
Solar radiation only, ISO 9060 Class C. Does not measure temperature, humidity or pressure.

GMX400
Temperature, humidity, pressure and rainfall, with no wind.

GMX500
Wind plus temperature, humidity and pressure. The standard MaxiMet.

GMX501
The GMX500 set plus solar radiation.

GMX550
The GMX500 set plus rainfall, optical or tipping bucket.

GMX551
Wind, T/H/P, rainfall and solar radiation. The most comprehensive integrated model.

GMX552
Wind and T/H/P plus black globe temperature, WBGT and Thermal Work Limit (TWL).

GMX560
Wind, T/H/P and a 6-axis compass for vessels, buoys and offshore. IP66 and IP68.

GMX600
Wind, temperature, humidity, pressure and optical rainfall, 0 to 300 mm/hr.

GMX603
The GMX500 set with the most accurate rainfall, 5% or better.
No single MaxiMet does all of that. Our team can suggest a pairing.
Specialist platforms
Two MaxiMet platforms built for one job each
Moving platforms and heat-stress monitoring each need something the standard range does not do. These two platforms do it.


Built for vessels, buoys and offshore platforms
- 6-axis compass keeps direction true on a moving platform
- IP68 as well as IP66, for salt, spray and immersion risk
- GMX260 measures wind. GMX560 adds temperature, humidity and pressure

WBGT and TWL for worker safety
- Wet Bulb Globe Temperature (WBGT) from one instrument
- Thermal Work Limit (TWL) to set safe work rates in the heat
- Black globe temperature, wind, temperature, humidity and pressure in the same unit
Not sure which fits? Speak to our team
Compare
Side by side, by the job you need it to do
Four common jobs, the models that do them, and only the figures that separate them. Every figure is from the released datasheet.
| Specification | Core weatherGMX500 | Adds rainfallGMX550 | Most accurate rainfallGMX603 | Rainfall and sunlightGMX551 |
|---|---|---|---|---|
| Choose it when | Wind, temperature, humidity and pressure are enough | You need rainfall with core weather | Rainfall accuracy matters most | You want everything from one instrument |
| Wind | 0 to 60 m/s | 0 to 60 m/s | 0 to 60 m/s | 0 to 60 m/s |
| Rainfall | No | Optical or tipping bucket | Optical, 0 to 200 mm/hr, 5% or better | Optical or tipping bucket |
| Solar radiation | No | No | No | 0 to 1600 W/m² |
| Heating | Optional, transducer | Optional, transducer | Optional, transducer | Optional, transducer |
| Weight | 0.7 kg | 0.7 kg | 1.1 kg | 0.8 kg |
| Datasheet | Datasheet | Datasheet | Datasheet | Datasheet |
| Specification | Rain and wind onlyGMX240 | Rain, no windGMX400 | Rain with full weatherGMX550 | Most accurate rainfallGMX603 |
|---|---|---|---|---|
| Choose it when | Temperature and pressure are measured elsewhere | You need rain with T/H/P and no wind | You need rain alongside wind and core weather | Rainfall accuracy matters more than anything |
| Rainfall | Optical, 0 to 300 mm/hr | Optical, 0 to 300 mm/hr | Optical or tipping bucket | Optical, 0 to 200 mm/hr, 5% or better |
| Wind | 0 to 60 m/s | No | 0 to 60 m/s | 0 to 60 m/s |
| T/H/P | No | Yes | Yes | Yes |
| TruMet PW100 | No | No | Pairs via tipping-bucket input | Built in |
| Weight | 0.5 kg | 0.5 kg | 0.7 kg | 1.1 kg |
| Datasheet | Datasheet | Datasheet | Datasheet | Datasheet |
| Specification | Sunlight onlyGMX301 | Sunlight and core weatherGMX501 | Sunlight, rain, full weatherGMX551 |
|---|---|---|---|
| Choose it when | You only need irradiance | You need irradiance with wind and T/H/P | You also need rainfall |
| Solar radiation | 0 to 1600 W/m², ISO 9060 Class C | 0 to 1600 W/m² | 0 to 1600 W/m² |
| Wind | No | 0 to 60 m/s | 0 to 60 m/s |
| T/H/P | No | Yes | Yes |
| Weight | 0.6 kg | 0.8 kg | 0.8 kg |
| Datasheet | Datasheet | Datasheet | Datasheet |
| Specification | Air conditions onlyGMX300 | Air conditions and rainGMX400 | Room for wind laterMetConnect THP |
|---|---|---|---|
| Choose it when | You need T/H/P and no wind | You need T/H/P and rainfall | You want T/H/P now, with inputs for a separate wind sensor |
| Rainfall | No | Optical, 0 to 300 mm/hr | Via rain gauge input |
| Sensors at different heights | No | No | Yes |
| Weight | 0.5 kg | 0.5 kg | See datasheet |
| Datasheet | Datasheet | Datasheet | Datasheet |
Why MaxiMet
A broader environmental picture without a collection of separate instruments
MaxiMet brings multiple meteorological measurements into a single compact platform, allowing engineers to select the combination of parameters that the application actually requires.
That can reduce the physical footprint of the installation, simplify deployment and avoid building a weather station from multiple separate instruments with their own mounting arrangements, wiring and interfaces.
MaxiMet gave the Mayflower Autonomous Ship its weather data across the Atlantic with nobody aboard. Designed and manufactured in Lymington, Gill technology is specified in 150+ countries.

The technology
Integrated measurement, configured around the application
MaxiMet uses ultrasonic technology for wind measurement alongside solid-state sensing for the other meteorological parameters included in each configuration.
Configurations combine wind speed and direction, temperature, humidity, pressure, precipitation and solar radiation, with compass and GPS on selected models. The station also calculates derived parameters on board:

Low maintenance
Ultrasonic wind measurement removes a source of mechanical wear
Selected MaxiMet configurations use ultrasonic technology for wind measurement, so there are no rotating cups, bearings or mechanical vanes in the wind-sensing process. There are no wind-speed components to lubricate or replace as part of normal operation.
This matters most when the station is installed somewhere that is expensive, inconvenient or time-consuming to access. A remote monitoring site, offshore platform or autonomous vessel can turn a seemingly minor maintenance requirement into a significant operational task. Reducing it reduces the number of interventions over the life of the installation.
- IP66 across the range, IP68 on the marine GMX260 and GMX560
- Optional low-power transducer heating for cold sites
- More than 40 years of Gill ultrasonic wind measurement
Power and integration
Designed to feed the systems that use the data. RS232, RS422, RS485, SDI-12 and Modbus, with USB through the MaxiMet communication cable, and Eco Mode for power-sensitive sites.
Download communications information →Configuration and software
MetSet configures compatible Gill weather stations, including communications settings. MetView displays the data they collect. Both are available through Gill technical resources.
Download MetSet and MetView →Environmental performance
Built for continuous measurement in exposed environments. IP66 across the range, IP68 on the marine models, and low-power heating for high-altitude, polar and other cold sites.
View technical specifications →Applications
Where local environmental data informs the wider system
The range of MaxiMet configurations lets the platform serve very different measurement requirements, from focused atmospheric sensing to broader environmental monitoring.
Marine and offshoreWind, heading and atmospheric conditions for vessels, buoys, offshore structures and marine monitoring systems, including dedicated configurations with enhanced environmental protection for exposed installations.Marine weather monitoring →
Renewable energySite assessment and operational monitoring around renewable-energy assets, where instruments stay exposed and unattended for long periods.Renewable energy →
Transport and infrastructureLocal weather for roads, bridges and buildings where wind, temperature and precipitation influence how the asset is operated.Transport and infrastructure →
AgricultureThe local conditions affecting crops, irrigation, spraying and wider agricultural operations, gathered from the ground the decisions are about.Agricultural weather monitoring →
Heat-stress monitoringGMX552 combines conventional meteorological measurement with black globe temperature, WBGT and Thermal Work Limit (TWL) for assessing environmental heat exposure.Heat-stress monitoring →Technical specification
Choose the measurements. Then choose the configuration.
| Configuration | Wind · T/H/P · Rain · Solar | Weight | Datasheet |
|---|---|---|---|
| GMX200 | 0.5 kg | Datasheet | |
| GMX240 | 0.5 kg | Datasheet | |
| GMX260 Marine | 0.5 kg | Datasheet | |
| GMX300 | 0.5 kg | Datasheet | |
| GMX301 | 0.6 kg | Datasheet | |
| GMX400 | 0.5 kg | Datasheet | |
| GMX500 | 0.7 kg | Datasheet | |
| GMX501 | 0.8 kg | Datasheet | |
| GMX550 | 0.7 kg | Datasheet | |
| GMX551 | 0.8 kg | Datasheet | |
| GMX552 Heat Stress | 1.29 kg | Datasheet | |
| GMX560 Marine | 0.7 kg | Datasheet | |
| GMX600 | 0.8 kg | Datasheet | |
| GMX603 | 1.1 kg | Datasheet |
Exact accuracy, power, dimensions, environmental limits, communications and model-specific options should remain tied to the relevant Gill datasheet as the technical source of record.
Accessories
MaxiMet accessories
Cables, mounts, set-up kit, add-on rain sensors and spares for the MaxiMet range. Pick a model to see only the parts that fit it.
In the box. Every MaxiMet ships with its mating connector (1405-PK-069).
Showing all 26 parts
Cables
- Cable, 4 pair, cut to length
- Cable, 4 pair, 15 m, pins fitted
- Retrofit cable, M12 to Clipper, 0.3 mFits GMX603
Connectors
- Spare connector
Mounting
- Bracket for wall mounting or pole clamping
- Support tube, 0.5 m
Set-up and configuration
- USB set-up cable, 1.8 m
Add-on rain sensors
- TruMet PW100 optical rain gaugeFits GMX550 and GMX551
- TruMet PW100 integration cable, 20 mFits GMX550, GMX551 and GMX603
- Optical rain sensorFits GMX550 and GMX551
- Optical rain sensor cable, 20 mFits GMX550 and GMX551
- Tipping bucket rain gaugeFits GMX550 and GMX551
- Tipping bucket rain gauge cable, 20 mFits GMX550 and GMX551
- Tipping bucket input connector, 4 wayFits GMX550 and GMX551
Spares
- Temperature and humidity sensor, serial numbers up to 2233xxxxNot for GMX200 or GMX240
- Temperature and humidity sensor, serial numbers 2234xxxx onwardsNot for GMX200 or GMX240
Heat stress spares
- Wet bulb sensor, 0.5 LFits GMX552
- Wet bulb sensor, 1 LFits GMX552
- Black globe, with locking screw and sealsFits GMX552
- Black globe temperature sensorFits GMX552
- Wet bulb PT100 temperature sensorFits GMX552
- Wet bulb sunshadeFits GMX552
- Wet bulb bottle and retainer, 0.5 LFits GMX552
- Wet bulb bottle and retainer, 1 LFits GMX552
- Wick and O-ring, 0.5 L wet bulbFits GMX552
- Wick and O-ring, 1 L wet bulbFits GMX552
Order accessories with your sensor or on their own. Quote the part number when you get in touch. See the accessories datasheet
Technical resources
Everything you need to specify, configure and deploy MaxiMet
Questions
Frequently asked questions
What is a weather station and what does it measure?
A weather station is a measurement system used to monitor atmospheric and environmental conditions at a particular location. Depending on the application, measurements can include wind speed and direction, temperature, relative humidity, atmospheric pressure, precipitation and solar radiation. The Gill MaxiMet range combines different combinations of these measurements within compact, integrated weather stations.
What sensors are typically used in a weather station?
A weather station can combine several sensing technologies depending on the parameters being measured. Wind speed and direction may be measured using ultrasonic or mechanical anemometers, while temperature, humidity, pressure, precipitation and solar radiation require different sensing technologies. Gill uses ultrasonic wind measurement alongside solid-state sensing across the MaxiMet range.
What measurements should a weather station have?
The appropriate measurements depend on what the system needs to understand or control. Wind speed and direction, temperature, humidity and pressure are common atmospheric measurements, while precipitation and solar radiation may be important for environmental monitoring, agriculture, renewable energy and research. The Gill MaxiMet range provides different combinations so the station can be specified around the application rather than simply selecting every available measurement.
What is the difference between a weather station and an anemometer?
An anemometer measures wind, typically providing wind speed and direction. A weather station combines wind measurement with other meteorological parameters such as temperature, humidity, pressure, precipitation or solar radiation. Gill manufactures both ultrasonic anemometers and integrated MaxiMet weather stations, allowing the measurement system to be selected according to the application.
What is the best weather station for environmental monitoring?
There is no single weather station that is best for every environmental monitoring application. The appropriate system depends on the parameters being measured, required accuracy, environmental conditions, power availability, communications and installation requirements. The Gill MaxiMet range is suited to applications where several meteorological measurements need to be collected from the same location within one compact platform.
What is the best weather station for remote monitoring?
The right weather station for remote monitoring depends on the measurements required, available power, communications, environmental exposure and how easily the site can be accessed. Low maintenance and efficient power consumption can become particularly important when routine visits are difficult. The Gill MaxiMet range provides compact configurations with low-power operation and ultrasonic wind measurement for applications where reducing maintenance is valuable.
What is the best weather station for marine applications?
Marine weather stations need to account for salt exposure, moisture, wind, movement and, depending on the application, heading and positioning. Environmental protection is therefore as important as the measurement capability. Gill MaxiMet Marine configurations are designed for marine deployment, with selected models providing enhanced environmental protection, compass functionality, GPS and heating options.
What is the advantage of an ultrasonic weather station?
An ultrasonic weather station uses ultrasonic measurement rather than rotating mechanical components to determine wind speed and direction. This removes cups, mechanical vanes and bearings from the wind-sensing process, reducing mechanical wear and the associated maintenance requirements. Gill has more than 40 years of experience in ultrasonic wind measurement and uses the technology across its wind sensors and MaxiMet weather stations.
Can MaxiMet calculate dew point and other derived meteorological parameters?
Yes. Depending on configuration, Gill MaxiMet can provide derived parameters including dew point, wind chill, air density, true wind, pressure at sea level, solar position and WMO wind averages and gusts. This allows the station to provide not only individual environmental measurements but also calculated information derived from them.
Have an application to discuss?
Speak to our team
Tell us what you need to measure, where and under what conditions. We’ll help you work out the appropriate approach.
Enquiring about MaxiMet
- You tell us the application What you measure, where and in what conditions.
- A real person reads it Not an account manager, and not a queue.
- We aim to respond in one working day Monday to Friday.





































