As temperatures begin warming up across the Seattle area and the long stretches of spring rain start slowing down, many homeowners begin asking the same question:
“When should I turn my irrigation system back on?”
In Western Washington, timing matters more than most people realize. Turn your sprinkler system on too early and you risk freeze damage or overwatering. Wait too long and your lawn, plants, and landscape can begin drying out before summer even arrives.
Every year, homeowners across Seattle, Tacoma, Bellevue, and Everett discover broken sprinkler heads, leaking valves, clogged nozzles, uneven watering, or irrigation schedules that waste water and damage lawns.
Before you start your irrigation system this spring, here are the 6 most important things to check.
1. Marke Sure Freezing Temperatures are Gone
Spring weather in the Pacific Northwest can still be unpredictable.
Even in April and early May, overnight temperatures can occasionally dip near freezing. If water is introduced back into irrigation pipes too early, frozen water expansion can crack fittings, damage valves, or split underground pipes.
For most homeowners in Seattle, Tacoma, Bellevue, and Everett, irrigation systems are typically safe to restart between:
- Late April
- Early May
- Mid-May during cooler years
A good rule of thumb: If overnight temperatures are consistently above 40°F, it’s usually safe to begin your irrigation startup.
Many homeowners wait until lawns begin actively growing and the weekly rain becomes less consistent before turning systems back on.
2. Check for Broken Sprinkler Heads
Winter weather, shifting soil, lawn equipment, and freezing temperatures often damage sprinkler heads without homeowners noticing.
Once your system is running, inspect every irrigation zone and look for:
- Sprinkler heads not popping up
- Cracked sprinkler bodies
- Uneven spray patterns
- Water spraying sidewalks or driveways
- Pooling water around a sprinkler head
Even one broken sprinkler head can waste a surprising amount of water throughout the summer. Broken or misaligned heads also create dry spots in lawns and uneven watering throughout landscape beds.
If certain areas of your lawn consistently turn brown during summer, poor sprinkler coverage is often the cause.
3. Look for Signs of Irrigation Leaks
A hidden irrigation leak can quietly increase your water bill for months. Common signs of a sprinkler system leak include:
- Soggy lawn areas
- Water bubbling from the ground
- Zones losing pressure
- Unusually green patches of grass
- Constant dripping after the system shuts off
Many homeowners in the Seattle area assume excess moisture is simply leftover spring rain, when in reality the irrigation system may already be leaking underground. Leaks commonly occur after winter due to:
- Freeze damage
- Cracked fittings
- Damaged valves
- Aging irrigation lines
- Worn sprinkler seals
Catching leaks early in spring can help prevent water waste and expensive repairs later in summer.
4. Adjust Your Watering Schedule for Seattle Weather
One of the biggest irrigation mistakes in Western Washington is watering too much during spring. Even though temperatures are warming up, the soil still holds significant moisture from winter rainfall.
Overwatering can lead to:
- Shallow grass roots
- Lawn fungus
- Moss growth
- Increased weed pressure
- Water runoff
- Plant stress
For most lawns in Seattle, Tacoma, Bellevue, and Everett, spring watering should remain relatively light.
A good starting point in May is:
- 1–2 watering days per week
- Early morning watering
- Shorter runtimes during cooler weather
As temperatures rise into July and August, watering schedules can gradually increase. Proper irrigation scheduling is one of the easiest ways to improve lawn health while reducing water waste.
5. Update Your Irrigation Controller Settings
Many homeowners forget their irrigation controller is still programmed for last summer’s heat. Spring irrigation schedules should be very different from peak summer schedules.
Before summer arrives, check:
- Start times
- Runtime lengths
- Seasonal adjustment settings
- Rain sensor functionality
- Backup batteries
If your controller resets during a power outage, it may default to incorrect watering schedules without you realizing it.
Modern smart irrigation controllers are becoming increasingly popular throughout the Seattle area because they automatically adjust watering based on:
- Rainfall
- Weather forecasts
- Temperature
- Seasonal conditions
Smart irrigation systems can help homeowners reduce water usage while keeping lawns healthier throughout the summer.
6. Don’t Ignore Dry Spots or Yellow Grass Early in the Season
Many homeowners assume lawn problems won’t appear until mid-summer, but irrigation issues often begin showing up in late spring. If you notice:
- Yellow grass
- Dry patches
- Uneven lawn growth
- Wilting plants
- Areas drying out faster than others
Common causes include:
- Misaligned sprinkler heads
- Low water pressure
- Clogged nozzles
- Poor sprinkler spacing
- Aging irrigation systems
Fixing these problems early helps prevent major lawn stress during the hotter summer months. Healthy irrigation systems should water evenly across the lawn without creating dry spots, puddles, or runoff.
For many homeowners, professional irrigation startup is worth it — especially if the system hasn’t been inspected in several years.
A professional irrigation startup service can include:
- Full irrigation system inspection
- Leak detection
- Sprinkler head adjustments
- Controller programming
- Water efficiency recommendations
- Minor repairs
- Coverage testing
Professional inspections often catch small issues before they become larger and more expensive summer repairs.
For homeowners in Seattle, Tacoma, Bellevue, and Everett, spring irrigation maintenance can also improve water efficiency during the drier summer months ahead.
Smart Irrigation Upgrades Seattle Homeowners Are Making in 2026
Many homeowners are upgrading older sprinkler systems to improve efficiency and reduce water waste. Popular irrigation upgrades include:
Smart Irrigation Controllers: Automatically adjust watering schedules based on real-time weather conditions.
Drip Irrigation Systems: Ideal for flower beds, shrubs, and landscape planting areas.
High-Efficiency Rotary Nozzles: Improve water absorption while reducing runoff.
Rain Sensors: Prevent unnecessary watering during wet weather.
These irrigation upgrades are especially useful in the Pacific Northwest, where weather conditions can shift quickly between wet spring months and dry summer conditions.
Frequently Asked Questions
Most homeowners in the Seattle area turn irrigation systems back on between late April and mid-May once freezing temperatures are unlikely.
Most lawns only need watering 1–2 times per week during spring depending on rainfall, soil conditions, and sun exposure.
This is commonly caused by low pressure, clogged sprinkler heads, leaks, or damaged irrigation valves.
Yes. Even small irrigation leaks can waste thousands of gallons of water over time.
Usually yes — but much less frequently than during summer. Spring irrigation should supplement rainfall, not replace it.
Common signs include dry spots, leaking sprinkler heads, soggy lawn areas, low pressure, unusually high water bills, and uneven watering.