Rain Sensors 101 – What They Are and Why Every Florida Lawn Needs One

Did you know that Florida law requires a functioning rain sensor on every automatic irrigation system? These small but mighty devices help prevent overwatering and protect our waterways—including the Indian River Lagoon.

What Is a Rain Sensor?

A rain sensor is a weather-sensing device that detects rainfall and automatically pauses your irrigation system. Once the sensor dries out, your system resumes normal operation. It prevents unnecessary watering when Mother Nature is already on the job.

A wireless rain sensor mounted on the edge of a rooftop gutter under a clear blue sky. A label in the top right corner reads "Example Wireless Rain Sensor" with a green checkmark. — *Rain sensors like this one detect rainfall and automatically shut off your irrigation system—saving water and preventing unnecessary runoff.*

Types of Rain Sensors

There are several types, but the most common for Florida homeowners include:

Wired rain sensors: Affordable and reliable; mounted on the roof or fence and wired directly into your irrigation controller.
Wireless rain sensors: Easier to install and offer greater placement flexibility.
Smart weather-based controllers: Often include built-in rain sensors and adjust irrigation based on real-time weather data.

Graphic showing three types of rain sensors: a wired sensor, a wireless sensor, and a smart controller. Each has a label and a checkmark banner that reads “Common Types of Rain Sensors.” — *Choose the rain sensor that fits your system and lifestyle—wired, wireless, or smart controllers all help prevent overwatering and protect the lagoon.*

Best Rain Sensors for Florida

Because of Florida’s heat and humidity, choose models that are:

UV-resistant and weatherproof
Adjustable for rainfall shutoff levels (e.g., ¼ inch, ½ inch)
Compatible with your irrigation controller brand

Where to Buy Them

Home improvement or hardware stores
Local irrigation supply companies
Online retailers

How to Install One

Most rain sensors can be installed in under 30 minutes:

Mount in an open, unobstructed area (roof, fence post, or rain gutter)
Connect to your irrigation controller’s sensor terminals (follow manufacturer instructions)
Set the desired rain shutoff level (usually ½ inch)

Wireless models may require syncing the sensor with a receiver on the controller.

How to Check If It’s Working

Use a cup of water to moisten the sensor and trigger shutoff
Run a manual irrigation test and see if the system pauses
Check the indicator light on wireless models

Maintenance Tips

Test your rain sensor monthly, especially before rainy season
Clear out debris or insects from the vents
Replace the moisture-absorbing discs every few years (some models use cork or hygroscopic materials)

Why It Matters

A working rain sensor helps you:

Stay compliant with Florida law
Prevent unnecessary runoff into the lagoon
Save money on your water bill
Keep your lawn healthy—not soggy

Install one today and make it part of your Lagoon Loyal lawn care routine!

References

Florida Legislature. (2023). Florida Statutes § 373.62. http://www.leg.state.fl.us/statutes
UF/IFAS Extension. (2019). Residential Irrigation System Rainfall Shutoff Devices. https://edis.ifas.ufl.edu/publication/AE221
U.S. EPA WaterSense. (2023). Outdoor Water Use in the U.S. https://www.epa.gov/watersense/outdoor
Hunter Industries. (2024). Mini-Clik Rain Sensor. https://www.hunterindustries.com
Rain Bird. (2024). RSD Series Rain Sensor. https://www.rainbird.com
St. Johns River Water Management District. (2023). Water Conservation Tips. https://www.sjrwmd.com/waterconservation/

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A man in an orange shirt and gloves installs a rain sensor on the gutter of a house in a sunny residential neighborhood. Palm trees, bushes, and a nearby yellow home with a red roof are visible in the background, evoking a typical Florida setting.