The amount of water your plants need and when it is needed changes with the weather, length of day, and root depth. By regularly adjusting the watering schedule of your automatic irrigation system (unless you have a smart timer), you can maintain healthy, beautiful plants and avoid wasting water.
In the Pacific Northwest, the watering season typically lasts from April through September. Check this page for advice on programming your sprinkler timer for the upcoming week. Interested in receiving weekly watering advice straight to your inbox? Sign up for the weekly water advice email! From March to October, we’ll send you a short email once per week that includes our watering advice and tips.
Weekly watering advice
Last updated: Friday, May 8, 2026
Conditions: Last week was warm, and this week was a bit milder. Similar temperate weather is expected into next week.
Watering recommendation:
- Established high-water-use plants: If the soil is dry 3 inches beneath the surface, water ½ inch once this week.
- Established deep-rooted plants with thick mulch over the soil: There is no need to water this week.
What’s the biggest difference between standard sprinkler timers and smart sprinkler or hose timers? Standard sprinkler timers run on fixed schedules that you set manually (which often leads to water waste!). Smart sprinkler and hose timers connect to the internet and automatically adjust watering based on real-time weather conditions. When it’s hot and sunny, they water more; when it’s cool, they water less. When it’s raining, they pause the system for a few days.
All of this can be managed from an app on your phone or tablet if you’re connected to Wi-Fi! (Don’t have Wi-Fi? Consider a smart sprinkler timer that uses a small onsite weather station to water according to the weather.)
Smart, weather-based sprinkler timers can reduce landscape water use by up to 25% compared to standard sprinkler timers.
Spring has arrived! Have questions about smart sprinkler timers and rebates for up to $100? Reach out to me at Mark.Guthrie@seattle.gov.
Resources
- Learn more about watering plants efficiently.
- Need some professional assistance? Check out this short list of local certified landscape professionals!
- If you’re interested in learning about supply conditions for Seattle’s regional water system, please visit Water Supply Conditions – Utilities | seattle.gov.
Choosing the right run time for your system
Each watering should apply a ½ inch of water. The application rate of a sprinkler system depends on the water pressure, system design, and system efficiency. Below are some general ranges of typical run times based on the precipitation rate of your sprinkler heads:
| Head Type | Nozzle Description | Run Time* for a ½ inch | If Using Cycles** | |
|---|---|---|---|---|
 | Spray Head | Sprays like a fan | 15-23 minutes | 3 cycles of 5-8 minutes |
 | Rotor Head | Single spray that rotates | 30-75 minutes | 3 cycles of 10-25 minutes |
 | MSMT Head | Multiple single sprays that rotate | 50-75 minutes | 3 cycles of 17-25 minutes |
**Cycling Recommendation: To prevent runoff and ponding in areas with clay soils and/or slopes, divide the run times into three cycles to allow the ground to absorb the water. Additional cycles are created by utilizing more than one start time combined with shorter runtimes.
If you have drip irrigation, follow these guidelines that include how many minutes it takes to water ¼ of an inch:
