FrostList

When to Test Your Sump Pump in Pasco, WA

SEASON PASSED260 days until spring thaw test (last 32°F)Mar 28

Check your Pasco sump pump before meltwater arrives — the last spring freeze averages March 28 — and again ahead of fall storms; the bucket test takes two minutes. Year to year the date swings about 35 days, which is why the live outlook beats the calendar.

OUTLOOK

Typical first spring thaw test (last 32°F) near Mar 28; local deadline about Mar 28. The live 10-day outlook loads here.

Local freeze dates for Pasco

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 18Oct 30Nov 15
28°F (hard freeze)Oct 27Nov 11Dec 1
24°F (severe)Nov 5Nov 25Dec 20

NOAA station: Kennewick · 2.0 mi away · 390 ft elevation.

For Pasco, the nearest NOAA station with freeze data is Kennewick, 2.0 miles out at 390 feet. Median first-freeze dates there run 32°F by Oct 30, 28°F by Nov 11, 24°F by Nov 25. Year to year the 28°F date has ranged from Oct 27 to Dec 1 — about 35 days apart. Spring's last 32°F freeze clears around Mar 28. Snowfall averages 2 inches a year, first reaching an inch near December.

The freeze arrives in two steps in Pasco: 32°F around Oct 30, then a hard 28°F near Nov 11. Year to year, the first 32°F night has fallen anywhere from Oct 18 to Nov 15 — about 28 days apart. Spring's final freeze lands near Mar 28 and as late as Apr 10, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Mar 28 — not snow load — drives the local prep list.

Your sump pump checklist

  1. Pour about five gallons of water into the pit slowly and watch the float rise, the pump start, and the water drop.
    Helpful gear: Water level alarm — Recommended pick
  2. Confirm the discharge line carries water 10–20 feet from the foundation and does not drain back into the pit.
    Helpful gear: Sump check valve — Recommended pick
  3. Clear the inlet screen and the pit of gravel and debris that can jam the float or the impeller.
  4. Check the check valve for a firm click; a failed valve lets discharged water fall back and short-cycle the pump.
  5. Add a battery backup pump so the system still runs when a storm knocks out the power.
    Helpful gear: Battery backup sump pump — Recommended pick
  6. Test the backup on battery power and note the install date; batteries usually need replacing every few years.
  7. If the primary pump is 7–10 years old, keep a replacement on the shelf before it fails mid-storm.
    Helpful gear: Replacement primary pump — Recommended pick
  8. Remember that flood insurance and most homeowner policies treat pump failure separately — read your coverage.

What to have on hand

Battery backup sump pump
Second pump that runs when the power goes out mid-storm.
Recommended pick
Water level alarm
Loud sensor that warns you before the pit overflows.
Recommended pick
Sump check valve
One-way valve that stops discharged water from draining back.
Recommended pick
Replacement primary pump
A ready spare for a pump nearing the end of its life.
Recommended pick

What this means locally

Compared with nearby cities, Pasco's first-freeze date near Mar 28 sits close to Kennewick (Mar 28) and about a week ahead of Richland (Apr 6). Washington's deadlines span Mar 2 to May 8 statewide — one date for all of Washington would be off by weeks for Pasco. Once you know Pasco's freeze date, use it to protect your pipes too.

Other winter jobs in Pasco

Every task below is dated to Pasco's own freeze and snow normals.

Sprinklers → Nov 1Frozen pipes → Oct 18Car battery → Nov 11RV → Nov 1Boat → Nov 4Motorcycle → Oct 30

See the full Pasco winter checklist, in order →

Frequently asked questions

How do I test my sump pump before heavy rain?
Pour about five gallons of water into the pit slowly and watch the float rise, the pump switch on, and the water level drop. Confirm the discharge carries water well away from the foundation. Doing this before the wet season, and again in spring near the last freeze around Mar 28, catches problems early.
How often should a sump pump run?
It varies with your water table and weather; some pumps cycle every few minutes during a storm and sit idle for weeks in dry spells. Frequent cycling with no rain can signal a stuck float, a failed check valve, or groundwater seeping in. Occasional running during wet weather is normal.
How long do sump pumps last?
A typical sump pump lasts about 7 to 10 years, though hard-working pumps wear out sooner. If yours is near that age, keep a replacement on hand so a mid-storm failure does not leave the pit unattended. Testing it seasonally tells you more than age alone.
Do I need a battery backup sump pump?
If your basement floods when the power goes out, yes — storms that overwhelm the pit are exactly when the grid tends to fail. A battery backup runs the pump through an outage, which is the single most common cause of a wet basement during heavy weather. Test the backup on battery power, too.
Does insurance cover sump pump failure?
Standard homeowner policies and federal flood insurance often exclude damage from a sump pump that fails or is overwhelmed. A separate water-backup or sump-failure rider may be available. Read your policy before a storm, because assumptions about coverage are a common and costly surprise.
Why is my sump pump running with no rain?
A high water table, snowmelt, or groundwater seepage can keep the pit filling even in dry weather. A pump that runs constantly may also have a stuck float switch or a check valve that lets discharged water fall back into the pit. Check the float and the valve first.

Data: NOAA 1991–2020 normals via Kennewick, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.