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, August 14, 2026
Conditions: It’s been mild, with similar conditions ahead.
Watering recommendation:
- Established high-water-use plants: If the soil is dry beneath the surface, water ½ inch twice this week.
- Established deep-rooted plants with deep mulch over the soil: If the soil is dry beneath the surface, water slowly and deeply until the top 6 inches of soil is wet.
Let’s Go Head-to-Head
Sprinkler systems are expensive and so is water! One common reason for an unexpectedly high water bill is poor “head-to-head” sprinkler coverage. This happens when each sprinkler’s spray doesn’t reach the next one. Sprinkler heads are designed to overlap their spray patterns, so each one’s spray reaches all adjacent sprinklers.
If sprinklers are spaced too far apart or some are missing, your system may need to run 2 to 3 times longer to give plants enough water. Over a season, this can waste hundreds of gallons! If your sprinklers aren’t reaching one another, consider replacing them with high-efficiency rotating nozzles. They spray water farther and use water more efficiently.
Have specific questions about your sprinkler system or our sprinkler timer replacement rebate? Reach out to Mark.Guthrie@seattle.gov.
Resources
- Learn more about water-efficient sprinkler systems
- 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:
