TROPO 4-inch Precipitation Gauge | FREE U.S. Shipping | Premium CoCoRaHS Gauge

(21 reviews)
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The TROPO Precipitation Gauge is the next generation 4-inch all-weather professional precipitation gauge that meets the accuracy and specification requirements of CoCoRaHS. The TROPO is the approved, premium CoCoRaHS* gauge option.

Included in the box:

  • Handle
  • Universal Mounting Bracket
  • Bird Deterrant Rods (x8)
  • Cap/Funnel
  • Inner Tube (mm. and inches)
  • Outer Tube (mm. and inches)
  • Three Precipitation Observation Forms (Climalytic Store Special)
  • Weatherproof Climalytic Decal (Climalytic Store Special)
  • 11" Cable Ties (x2)
  • Wood Screws (x2)
  • Adhesive Strip (For frictional grip to pole mount applications)
  • Extra Long Cleaning Brush
  • Bubble Level
  • Installation and User Guide (also available HERE)
  • 10% Off your next order coupon (Climalytic Store Special)

The TROPO is the first comprehensive refresh of the 4-inch Stratus All-weather Rain Gauge, which was first introduced way back in 1973! Based on the design of NOAA’s National Weather Service official standard 8” rain gauge, the TROPO Precipitation Gauge uses the same dual cylinder design to measure precipitation with a resolution of 0.01” (.25 mm).

The inner cylinder holds 1 inch (25 mm) of precipitation, while the extra-large outer cylinder holds another 12.50 inches (317.5 mm) of precipitation making the maximum capacity approximately 13.5” (343 mm). The inner cylinder and funnel top cap are removable to allow catchment of snowfall or other frozen precipitation, which can then be melted down or weighed to determine a liquid equivalent.

The gauge is made of a UV stabilized Polycarbonate; the same weather resistant material as greenhouses.

This is the most advanced, accurate and easy-to-use manual precipitation gauge available.

For more details see TROPO page.

Note: Custom station ID labels are sold separately (see TROPO - Parts) and were included with all pre-orders from March - April, 2023 as a complimentary thank you.  



  • 13.5” (342.9 mm) maximum capacity
  • Textured grips on outer cylinder for secure handling of the gauge
  • Bird deterrent rods (optional)
  • Funnel opening atop inner cylinder for easy filling without outer tube cap.
  • Outer cylinder gradations for quick, estimated readings
  • Removable handle for easy handling of the unmounted gauge.
  • Flexible, easy mounting bracket for pole or post installation with weather-protected bracket design for easy mounting & unmounting
  • Inner cylinder equipped with stabilizing base for easy filling
  • Locking funnel cap to avoid blow-offs
  • Extra tall cap walls for more accurate catchment of precipitation
  • Beveled guide on bottom of outer cylinder allows inner cylinder to easily slide in place.
  • Safe, easy operation with textured grips and removable handle
  • Attain more accurate precipitation measurements with fewer measurement mishaps
  • Save time cleaning the gauge from bird droppings
  • Save time and avoid potential damage while dismounting gauge in icy or frozen conditions
  • Save money by not buying blown off and lost cap/funnel
  • Fewer gauge over-toppings during extreme events or long accumlation periods
  • Save time installing and operating the gauge


PACKAGING NOTICE: This product may ship in a box that reveals its contents. If this is a concern, please contact us to see if other options are available.

* A portion of proceeds are donated to CoCoRaHS!


A list of features that the TROPO has over other manual gauges: pole mounting bracket, freeze-proof, lasting clarity, metric and imperial units, 13.5" max capacity, textured grips, outer cylinder graduations, pour spout, inner cylinder funnel, inner cylinder seat, optional bird spikes, tall cap, locking cap, removable handle, included brush.



  • 3

    Review by Jim Krestensen

    Got mine in today and very impressed! Although the installation instruction fails to mention how high does the top of the cap/funnel have to be from the top of the beveled edge of a 4x4. on the other the rain gauge the instruction mentions this! Cannot find any other information so that I can correctly install the Tropo.

  • 5
    Rain Review

    Review by Joshua Ortiz Rosario

    Great product to read rain acumulations and a new inversion for CoCoRaHS.

  • 5
    So Well Done

    Review by Mike Jewell

    Loving this rain gauge. It is so very well designed, manufactured and packaged. I drove a metal fence post in the ground and had it mounted and ready for rain in about 30 minutes. I have a Davis electronic, automated rain gauge that is super convenient to use/read but it's nowhere near as fun as actually seeing the water collect and getting a much better "feel" for just how much rain is 0.02 inches. Or 1.67 inches! Well done Climalytic!

  • 5
    Tropo gauge

    Review by Kevin S.

    The Tropo rain gauge is great. It is made with high quality materials that give it a great fit and finish. It is also extremely clear, which makes taking readings even easier. I also love that the top snaps on keeping it in place, and that the inner tube has the funnel built into it making the whole thing easier. I highly recommend to anyone looking for a high quality gauge.

  • 5
    Climalytic TROPO rain gauge

    Review by Bob Valen

    I installed the gauge the day in it arrived. A few days later we had a nice rain event. The reading of the gauge is much more precise and easy than my old gauge. This is truly a scientific instrument.

  • 5
    Science / Art?

    Review by Randall Yates

    It's a thing of beauty and scientific! Can't wait for some rain. Thank you.

  • 5
    "The mathematically computed slight taper of the cylinders and laser controlled post-process engraving has produced what appears to be a very accurate instrument..."

    Review by Michael Sparks, Kentucky CoCoRaHS observer

    Out-of-the-box I was impressed by the crystal clear optical clarity of the cylinder material, and the sharp resolution of the laser engraving. A comment on the material: Based on specifications, I believe the material used will have longer clarity life using its UV enhanced material. This state-of-the-art construction almost felt 'flimsy' at first, because of appearance and material, compared to the 'other name', but it is at least as strong-- maybe stronger. Impressive. The outer cylinder measurement lines are an impressive addition, just be sure to use them as an approximation, as emphasized in the documentation. I compared the inner cylinder measurements (water density/weight measurements), with 6 "other name" cylinders of various production cycles, and found the Tropo one hundred percent consistent from .01" to 1", while the "other" name varied from 2%-10% across various volumes/cylinders. And, out of curiosity, on this specific instrument, I DID check the outer gauge markings 'for approximations', and determined, that on this production run, they were very accurate, but will state again, they're NOT to be used for measurement, follow the decant procedure. The mathematically computed slight taper of the cylinders and laser controlled post-process engraving has produced what appears to be a very accurate instrument, within it's resolution of 0.01". The funnel design of the inner cylinder is very convenient for outer cylinder decant into the inner cylinder. Even easier with the 'pour' spout molded in the outer cylinder! Just note the position of the Tropo's precision 1" overflow slot, to avoid decant spillage. Again, the 6 "other name" cylinders 1" overflow varied from -0.02" to +.03". I believe the 'nesting' design will aid in preventing evaporation loss. Upper cap has a 'locking' feature to minimize 'blow offs' which MAY be a little 'tight' on first few uses. The unit came with 8 optional bird spikes, which are obviously sharp, and with that snap-on cylinder cap, I'd urge care with my hands/eyes. I added tiny silicon tips to mine. There has been effort and thought into the cylinder designs, most not obvious at first... e.g. seating the inner cylinder into the outer is remarkable easy, compared to the 'hit-or-miss' balancing act on the 'other name'. The mounting bracket design and construction is a major innovation. It inserts easily, and 'snaps' slightly to lock. More importantly, it required just a minor tap to free when 'frozen', compared to very difficult removal on the 'other name' gauge. I did not evaluate the 'pole' mount, though that design is similar to the 'post' bracket. The addition of an add-on handle should prove welcome to those in high precip regions, especially since this will hold 13" liquid! I initially found it slightly cumbersome and a bit awkward during the few opportunities, choosing to utilize those wonderful finger grip moldings on the outer cylinder. Like anything new, some experience will prove its value!

  • 5
    "I expect TROPO will be the premier manual rain gauge for years to come."

    Review by Ric W. (New Hampshire CoCoRaHS Observer)

    From careful measurements by weight it is clear that TROPO is more accurate than similar 4" rain gauges on the market. The longer inner tube is easy to read. I expect TROPO will be the premier manual rain gauge for years to come.

  • 5
    "Sleek design, highly accurate, easy to mount, and simple to use."

    Review by Cheryl J. - Southwestern OR (NWS Spotter and CoCoRaHS daily reporter)

    Sleek design, highly accurate, easy to mount, and simple to use. Some highlights that will not disappoint: Easy slide on/slide off secure/sturdy mounting bracket, convenient pour spout on the large tube and a brilliantly designed handle that slides onto the outer tube's mounting bracket to pour off your precip in excess of 1" into the inner tube. As a beta tester, I feel privileged to evaluate this excellently designed rain gauge and provide feedback to make it a better product for a wider audience.