Approved Rain Gauges


These rain gauges have been field-tested and meet accuracy standards established by the National Weather Service.


Why Isn't My Rain Gauge on this Approved List?

Click here for our page about gauge mounting and installation tips.

Stratus - by Productive Alternatives

This is the most common gauge in the network and meets the minimum requirements set by the National Weather Service to be within +/- 4% of the Standard Rain Gauge (SRG) in all types of weather.

This is the most affordable gauge.



Basic image of the Stratus rain gauge by Productive Alternatives

TROPO - by Climalytic Instruments, LLC

CoCoRaHS Headquarters is pleased to designate the TROPO rain gauge, manufactured by Climalytic Instruments, LLC, as another approved manual 4-inch rain gauge for CoCoRaHS. Field testing has demonstrated the TROPO rain gauge is accurate, and it incorporates observer-friendly features such as greater capacity, improved mounting bracket, and multiple mounting options.

This gauge is considered premium and is therefore more expensive than the Stratus.

TROPO rain gauge manufactured by Climalytic Instruments LLC


Standard Rain Gauge (SRG) - by the National Weather Service

The 8-inch gauge used in the National Weather Service is of a standardized design used throughout the world for official rainfall measurements. This standardization provides uniformity, continuity, and credibility of precipitation data worldwide.

This gauge is the most expensive and is not commonly used other than for co-located COOP stations associated with the National Weather Service.

Standard Rain Gauge (SRG) by the National Weather Service



Why Isn't My Rain Gauge on the Approved List?

Digital/electronic rain gauges are not approved for CoCoRaHS use. This includes Davis, Ambient, La Crosse, AcuRite, and many others. Click here to see a more detailed discussion of why digital gauges are not acceptable.


All manual rain gauges are not the same. There are a number of "off-brand" 4-inch gauges available online, including Outback Blue and others. These are not approved for CoCoRaHS use!  Gauges commonly found in hardware stores, big box home stores, and garden centers are usually not calibrated to measure to the nearest 0.01 inch, nor do they have the capacity of the 4-inch manual gauge.