FrostList

When to Test Your Sump Pump in Tempe, AZ

SEASON PASSED217 days until spring thaw test (last 32°F)Feb 13

Two moments stress a Tempe sump pump: the spring thaw near February 13 and the fall rainy season, so test before each with a five-gallon bucket in the pit. The early-to-late range spans roughly 53 days, so treat the median as a midpoint, not a promise.

OUTLOOK

Typical first spring thaw test (last 32°F) near Feb 13; local deadline about Feb 13. The live 10-day outlook loads here.

Local freeze dates for Tempe

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 18Dec 5Dec 24
28°F (hard freeze)Nov 27Dec 19Jan 19
24°F (severe)Dec 4Dec 31Jan 24

NOAA station: Tempe Asu · 1.1 mi away · 1,167 ft elevation.

The reference station for Tempe is Tempe Asu (1.1 mi, 1,167 ft). First freeze there: 32°F by Dec 5, 28°F by Dec 19, 24°F by Dec 31. That hard freeze has landed anywhere from Nov 27 to Jan 19, a swing of roughly 53 days. Spring's last 32°F freeze clears around Feb 13.

Expect the first frost near Dec 5 in Tempe and the first hard freeze by about Dec 19. The 32°F date swings from Nov 18 at its earliest to Dec 24 at its latest, near 36 days. The last spring freeze averages Feb 13 and as late as Mar 9, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Feb 13, is the one that matters.

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, Tempe's first-freeze date near Feb 13 sits close to Scottsdale (Feb 13) and close to Mesa (Feb 13). Arizona's deadlines span Jan 4 to Jun 4 statewide — one date for all of Arizona would be off by weeks for Tempe. Once you know Tempe's freeze date, use it to protect your pipes too.

Other winter jobs in Tempe

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

Sprinklers → Dec 9Frozen pipes → Nov 18Car battery → Dec 19RV → Dec 9Boat → Dec 12Motorcycle → Dec 5

See the full Tempe 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 Feb 13, 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 Tempe Asu, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.