FrostList

When to Test Your Sump Pump in Lewisville, TX

SEASON PASSED246 days until spring thaw test (last 32°F)Mar 14

Two moments stress a Lewisville sump pump: the spring thaw near March 14 and the fall rainy season, so test before each with a five-gallon bucket in the pit. The early-to-late range spans roughly 41 days, so treat the median as a midpoint, not a promise.

OUTLOOK

Typical first spring thaw test (last 32°F) near Mar 14; local deadline about Mar 14. The live 10-day outlook loads here.

Local freeze dates for Lewisville

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 2Nov 17Dec 4
28°F (hard freeze)Nov 9Nov 29Dec 20
24°F (severe)Nov 18Dec 13Jan 14

NOAA station: Grapevine Dam · 7.5 mi away · 585 ft elevation.

Numbers for Lewisville come from Grapevine Dam, 7.5 miles away at 585 feet, where the medians fall 32°F by Nov 17, 28°F by Nov 29, 24°F by Dec 13. The 28°F freeze has come as early as Nov 9 and as late as Dec 20, a 41-day spread. Spring's last 32°F freeze clears around Mar 14. Snowfall averages 0 inches a year.

Lewisville usually sees its first 32°F night about Nov 17, with the first 28°F hard freeze close behind near Nov 29. The 32°F date swings from Nov 2 at its earliest to Dec 4 at its latest, near 32 days. The last spring freeze averages Mar 14 and as late as Apr 3, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Mar 14, 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

Lewisville freezes later than The Colony (Mar 7) and close to Flower Mound (Mar 14) — a reminder that even nearby towns differ by days. Statewide, Texas prep dates run Jan 8 through Apr 15, which is why Lewisville gets its own number rather than a Texas-wide average. The same freeze also decides when to protect your pipes.

Other winter jobs in Lewisville

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

Sprinklers → Nov 19Frozen pipes → Nov 2Car battery → Nov 29RV → Nov 19Boat → Nov 22Motorcycle → Nov 17

See the full Lewisville 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 14, 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 Grapevine Dam, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.