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Lewisville weather by month: averages, rainfall & climate trends

Seasons run to extremes in Lewisville: monthly means span 40.2°F between the coldest month and the warmest. Rainfall leans toward the stretch from March to May. Lewisville weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+5.6°Fhigh well above average

80° / 58°Today
74° / 55°Average
see today in detail →

How it's changed

+3.3°Faverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4918frost days a year now (2016–2025) · 22 in the 1940sfrost days a year · 22 in the 1940s137days above 86°F a year now (2016–2025) · 97 in the 1940sdays above 86°F · 97 in the 1940s+3.3°F vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 2.3 incheshigh 56°low 37°February, rain 2.7 incheshigh 60°low 41°March, rain 3.6 incheshigh 68°low 48°April, rain 4.5 incheshigh 76°low 57°May, rain 5.5 incheshigh 83°low 65°June, rain 3.1 incheshigh 90°low 72°July, rain 1.7 incheshigh 94°low 76°August, rain 1.8 incheshigh 95°low 76°September, rain 2.7 incheshigh 88°low 69°October, rain 3.4 incheshigh 78°low 59°November, rain 3.3 incheshigh 67°low 48°December, rain 2.7 incheshigh 58°low 40°wettest month May, 5.5 inches · 37.4 inches a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

78.6°

78°feels like
34%humidity
48°dew point
5 mphfrom SE
UV index4.9
sunrise07:41sunset18:42day length11h 01m
TodayOvercast80°58°
TueOvercast74°63°
WedClear82°61°
ThuOvercast80°72°
FriOvercast74°62°
SatOvercast76°63°
SunOvercast84°66°

On this date: October 26

Today (forecast)
80° / 58°
Average for October 26
74° / 55°

High well above average · +5.6°F

  • Highest since 1940: 90.6° · 1950
  • Lowest since 1940: 36.9° · 1957
  • One year ago: 73° / 60°

Every October 26 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 26 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Lewisville is sampled from the ECMWF ERA5 reanalysis at 33.05°N, 96.99°W, with daily records since 1940.

Coordinates
33.05°N, 96.99°W
Time zone
America/Chicago
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

23 of the last 31 days were warmer than the historical average for that date. Average difference: +4.3°F.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

The year peaks in July, at around 94.2°F by mid-afternoon, with nights around 75.9°F. Around 135 nights a year stay above 68°F. The coolest month is January, when afternoons reach about 55.8°F and overnight lows sit around 37.1°F. Frost shows up on around 20 mornings a year.

In total, Lewisville averages about 37.4 inches of precipitation a year; May is usually the wettest month (5.5 inches) and July the driest (1.7 inches).

Over the full record (since 1940), the annual mean temperature in Lewisville has risen by 3.3°F between its first decade and its last. The count of days past 86°F has risen from roughly 95 a year to 135 between the record's first and last decades.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 40°F. Wettest month: May (~5.5 in). Whole year averages ~37.4 inches of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 71 rainy days a year: most in May (~9), fewest in August (~4).

Bars = average number of days with ≥ 0.08 in per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Lewisville month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January55.8°37.1°2.3 in510.0 h83.7° (1951)7.9° (1982)
February60.3°40.8°2.7 in610.8 h91.6° (2024)−0.2° (2021)
March68.3°48.1°3.6 in711.8 h98.3° (1974)15.7° (2014)
April76.2°56.5°4.5 in812.8 h98.6° (2006)31.3° (1975)
May82.6°64.8°5.5 in913.7 h101.4° (1985)40.3° (2013)
June89.8°72.4°3.1 in614.2 h106.3° (1980)54.1° (1964)
July94.2°75.9°1.7 in414.0 h108.1° (2022)61.0° (1971)
August94.6°75.6°1.8 in413.2 h109.4° (2023)59.0° (1992)
September87.8°68.9°2.7 in512.2 h108.4° (2023)43.1° (1984)
October78.4°58.6°3.4 in611.2 h96.5° (2014)27.5° (1993)
November66.6°47.9°3.3 in510.3 h91.6° (2017)20.9° (1976)
December58.3°40.3°2.7 in69.8 h88.9° (1955)−0.1° (1989)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +3.3°F.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.36°F per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Mar–May is warming fastest: +0.46°F per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 86°F per year: 97.2 early in the record → 137.0 recently. Frost days: 22 → 18.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2023, coldest in 2021: 109.4°F / −0.2°F.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~37.4 in/year on average. Last decade: +5% vs that average. Long-term trend: +0.65 in per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Lewisville

Which is the warmest month in Lewisville?
On long-term average, the warmest month in Lewisville is July (mean daily temperature of about 84.7°F) and the coolest is January (about 44.5°F).
How does today's temperature in Lewisville compare to the historical average?
On October 26, 2026, Lewisville is forecast to reach a high of 80.1°F and a low of 57.7°F. The long-term average for this date (the full record since 1940) is a high of 74.4°F and a low of 55.0°F, so today's high is 5.6°F warmer than that average.
How much has Lewisville warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Lewisville is about 3.3°F warmer.
How much does it rain in Lewisville?
Lewisville receives about 37.4 inches of precipitation per year on long-term average, with May typically the wettest month.
What is the average temperature in Lewisville?
Over the full record (since 1940), the annual mean temperature in Lewisville is about 65.6°F. The warmest month is July and the coolest is January.
What are the average temperatures in Lewisville by month?
Average daily highs and lows for each month in Lewisville (°F, full record since 1940): January 56°/37°, February 60°/41°, March 68°/48°, April 76°/57°, May 83°/65°, June 90°/72°, July 94°/76°, August 95°/76°, September 88°/69°, October 78°/59°, November 67°/48°, December 58°/40°.
What is the weather like in Lewisville in summer?
Summer in Lewisville (June to August) is hot. Daytime highs sit at 90–95°F and nights at 72–76°F; August is the warmest month. Rain falls off from 3.1 inches on 6 days in June to 1.8 inches on 4 days in August.
What is the weather like in Lewisville in winter?
December to February is winter in Lewisville, and it is cool. Afternoons run 56–60°F and nights 37–41°F; January is the coldest month. Rain falls on about 6 days a month, adding up to around 2.6 inches.
What is the weather like in Lewisville in spring?
Spring in Lewisville (March to May) is wet and pleasantly warm. March is still 68°F in the afternoon and 48°F at night, May already 83°F and 65°F. Rain rises from 3.6 inches on 7 days in March to 5.5 inches on 9 days in May. It is the wettest season of the year.
What is the weather like in Lewisville in autumn?
Autumn in Lewisville (September to November) is pleasantly warm. It cools from 88°F by day and 69°F at night in September to 67°F and 48°F in November. Rain falls on about 5 days a month, adding up to around 3.2 inches.
How many days a year does it rain in Lewisville?
On long-term average, Lewisville has about 71 days a year with at least 0.08 inches of rain or snow. The annual total is roughly 37.4 inches.

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