How Often Should You Water Your Lawn in Kennewick, WA?
If you're a homeowner in Kennewick, WA, you already know we live in a region where sunshine dominates and rainfall is rare during the summer. That means your lawn relies heavily on you for hydration—and finding the right watering schedule is key to keeping your grass healthy without overdoing it.
Here’s a local guide to help you know how often (and how much) to water your lawn in Kennewick’s unique climate.
Knowing Kennewick's Local Climate
Kennewick is part of Washington’s semi-arid region, with hot, dry summers and mild winters. On average, the area gets only about 7–9 inches of rainfall per year, most of it falling between November and March. That means your lawn will need supplemental irrigation from April through September, especially when temps soar into the 90s and beyond.
Monthly Watering Schedule Breakdown
Kennewick’s weather swings from damp winters to bone-dry summers, so your watering plan should adapt each month. Below is a month-by-month guide to help you optimize lawn health and conserve water during the irrigation season.
March
- Frequency: 1x per week (only if needed)
- Amount: 0.5–0.75 inches per week
- Considerations:
- March can still bring some rain and cold nights.
- Begin watering only if the soil is dry and temps rise above 50°F consistently.
- Tips:
- Test soil moisture by inserting a screwdriver; if it goes in easily, skip watering.
- Start slowly to encourage deep root growth as the lawn comes out of dormancy.
April
- Frequency: 1–2x per week
- Amount: 0.75–1 inch per week
- Considerations:
- Temperatures start to rise, but spring showers may supplement irrigation.
- Windy days increase evaporation—water early in the morning to minimize loss.
- Tips:
- Aerate your lawn this month to improve water absorption, especially in compacted soils.
- Consider fertilizing mid-to-late April to support spring growth.
May
- Frequency: 2x per week
- Amount: 1–1.25 inches per week
- Considerations:
- Grass is actively growing. Warm, dry weather increases the need for irrigation.
- Begin a regular watering schedule if you're not seeing consistent rainfall.
- Tips:
- Use a rain gauge or even just tuna cans to measure how much water your sprinklers deliver.
- Adjust sprinkler heads for even coverage and avoid sidewalks or driveways.
June
- Frequency: 2–3x per week
- Amount: 1.25–1.5 inches per week
- Considerations:
- The summer heat ramps up, but evaporation also increases—timing matters.
- Tips:
- Water between 6 a.m. and 10 a.m. for best absorption.
- Consider using smart irrigation controllers to optimize timing and conserve water.
July
- Frequency: 3x per week (if permitted)
- Amount: 1.5–2 inches per week
- Considerations:
- July is typically the driest month (average rainfall: ~0.2 inches).
- Lawns need consistent moisture to stay green and stress-free.
- Tips:
- Follow KID’s voluntary schedule: Water on assigned days to help spread supply. Find more info below.
- Mulch grass clippings instead of bagging—they retain moisture and add nutrients.
August
- Frequency: 2–3x per week
- Amount: 1.25–1.5 inches per week
- Considerations:
- Still hot and dry, but temperatures may slightly taper by the end of the month.
- Tips:
- If using rotary sprinklers, allow time for multiple passes to prevent runoff.
- Check soil moisture levels every few days—adjust if soil is staying too wet or too dry.
September
- Frequency: 1–2x per week
- Amount: 1 inch per week
- Considerations:
- Cooler nights and occasional rainfall reduce watering needs.
- Lawns may begin slowing growth, but roots are still active.
- Tips:
- Ideal month for overseeding and lawn renovation.
- Water deeply after any seeding to encourage germination.
October
- Frequency: 1x per week (or less, depending on rainfall)
- Amount: 0.5–0.75 inches per week
- Considerations:
- Temperatures drop, and rainfall picks up.
- Begin tapering off irrigation.
- Tips:
- Shut off irrigation if there’s measurable rainfall in the forecast.
- Start preparing your system for winterization.
November – February
- Frequency: Rarely needed
- Amount: Rely on natural precipitation
- Considerations:
- Lawns go dormant or significantly slow in growth.
- Irrigation systems should be winterized to prevent damage.
- Tips:
- Inspect for compacted areas or drainage issues during wet months.
- If there are long stretches without rain and temps are above freezing, one deep watering per month may help prevent root desiccation.
Summer Considerations (June – August)
Kennewick summers are hot, dry, and full of sunshine—which means your lawn needs more attention and smarter watering habits to stay healthy without wasting water. The Kennewick Irrigation District (KID) emphasizes the importance of voluntary conservation during the 2025 irrigation season to ensure long-term water availability for everyone in the region.
Stick to KID’s Suggested Watering Days
Kennewick Irrigation Disctrict (KID) encourages homeowners to water on assigned watering days to balance irrigation demand and avoid overloading the system. These suggested days help reduce peak usage and improve overall system efficiency. For current updated, please check out their KID's Drought Information page.
Early Morning is Best
Water your lawn between 6 a.m. and 10 a.m. when temperatures are cooler and wind is minimal. This reduces evaporation loss and ensures more water reaches the roots. Avoid watering midday or in the evening, as that can lead to evaporation or fungal growth.
Use the “Cycle and Soak” Method
Instead of watering all at once, split your watering time into two or three shorter cycles, spaced 30–60 minutes apart. This helps prevent runoff, especially on clay or compacted soils that struggle to absorb water quickly. For example:
- 10 minutes on → rest → 10 more minutes on
Adjust Your System Monthly
As temperatures rise from June to July and taper off in August, so should your watering schedule. Most lawns need 1.5–2 inches of water per week during peak heat in July. Use a rain gauge or empty tuna can to measure how much water your sprinkler actually delivers.
Watch for Wind and Overspray
Kennewick often sees breezy afternoons that scatter sprinkler spray. Make sure your irrigation system is targeting grass—not pavement—and adjust nozzles to prevent overspray onto sidewalks or driveways.
Check for Leaks & Tune-Up Your System
KID stresses the importance of regularly inspecting your irrigation system for broken heads, leaks, or inefficient zones. A single leaky valve or cracked pipe can waste thousands of gallons during the season.
Know When to Let It Go Dormant
Grass species like Kentucky bluegrass may naturally go dormant in extreme heat. It’s okay to let your lawn brown temporarily to conserve water—as long as you give it a deep soak (0.5–1 inch) every 3–4 weeks to keep the roots alive.
Consider Landscape Improvements
Long-term water savings can come from:
- Replacing thirsty turf with drought-tolerant grasses like Tall Fescue
- Installing drip irrigation for flower beds and borders
- Adding mulch to retain moisture and protect plant roots from extreme temps
Let Jeff’s Irrigation & Landscaping Help You Maximize Every Drop
At Jeff’s Irrigation & Landscaping, we specialize in irrigation installation and maintenance tailored for Kennewick’s unique climate and soil conditions. Whether you need a new sprinkler system, seasonal tune-ups, or smart upgrades to reduce water waste, our experts have you covered.
We also offer landscaping consultations to help you choose the right grass types, plant selections, and design elements that thrive in the Tri-Cities' hot, dry summers—all while using less water.
Ready to make the most of your watering this season? Contact Jeff’s Irrigation & Landscaping today and let’s build a lawn that’s green, efficient, and sustainable.