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Deer Valley weather by month: averages, rainfall & climate trends

Seasons run to extremes in Deer Valley: monthly means span 41.0°F between the coldest month and the warmest. Rainfall is on the low side overall. Deer Valley weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−3.9°Fhigh below average

80° / 55°Today
83° / 58°Average
see today in detail →

How it's changed

+4.4°Faverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–490frost days a year now (2016–2025) · 6 in the 1940sfrost days a year · 6 in the 1940s193days above 86°F a year now (2016–2025) · 171 in the 1940sdays above 86°F · 171 in the 1940s+4.4°F vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 1.3 incheshigh 65°low 43°February, rain 1.2 incheshigh 69°low 46°March, rain 1.2 incheshigh 75°low 50°April, rain 0.4 incheshigh 84°low 57°May, rain 0.1 incheshigh 92°low 65°June, rain 0.1 incheshigh 102°low 74°July, rain 0.6 incheshigh 105°low 82°August, rain 1.0 incheshigh 103°low 81°September, rain 0.9 incheshigh 98°low 74°October, rain 0.8 incheshigh 87°low 62°November, rain 0.9 incheshigh 74°low 51°December, rain 1.3 incheshigh 66°low 44°wettest month January, 1.3 inches · 9.9 inches a yearsee month by month →

Right now

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

Right now

64.4°

61°feels like
50%humidity
45°dew point
5 mphfrom NE
UV index0.0
sunrise06:41sunset17:43day length11h 01m
SunClear80°55°
TodayClear84°59°
TueClear83°55°
WedOvercast82°72°
ThuOvercast82°73°
FriDrizzle77°67°
SatMostly clear76°66°

On this date: October 26

Today (forecast)
80° / 55°
Average for October 26
83° / 58°

High below average · −3.9°F

  • Highest since 1940: 95.8° · 2024
  • Lowest since 1940: 44.1° · 1970
  • One year ago: 86° / 62°

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 Deer Valley is sampled from the ECMWF ERA5 reanalysis at 33.68°N, 112.13°W, with daily records since 1940.

Coordinates
33.68°N, 112.13°W
Time zone
America/Phoenix
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

18 of the last 31 days were warmer than the historical average for that date. Average difference: +1.1°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 warmest month is July, with typical afternoon highs of 105.1°F and nights around 81.9°F. In a typical recent year, around 195 days reach 86°F or more. The coolest month is January, when afternoons reach about 65.2°F and overnight lows sit around 42.9°F.

Deer Valley picks up roughly 9.9 inches a year, with a peak of 1.3 inches in January and as little as 0.1 inches in June.

Comparing the record's first decade with its most recent one, Deer Valley now averages 4.4°F warmer than it did in the 1940s. That last decade has also been the warmest in the record.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 41°F. Wettest month: January (~1.3 in). Whole year averages ~9.9 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 23 rainy days a year: most in January (~3), fewest in June (almost none).

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.

Deer Valley 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
January65.2°42.9°1.3 in310.0 h87.7° (1971)22.6° (1949)
February69.4°45.6°1.2 in310.8 h90.7° (1963)24.4° (1985)
March75.2°50.0°1.2 in311.7 h97.1° (2007)28.3° (1966)
April83.8°56.7°0.4 in112.8 h102.3° (1992)37.4° (1953)
May92.4°65.2°0.1 in013.7 h110.8° (1984)42.6° (1967)
June101.9°74.2°0.1 in014.2 h118.1° (1990)51.3° (1950)
July105.1°81.9°0.6 in114.0 h119.4° (1995)65.6° (1992)
August102.9°80.7°1.0 in213.3 h115.4° (2003)60.9° (1968)
September98.1°73.9°0.9 in212.2 h113.6° (1950)53.0° (1965)
October87.1°61.9°0.8 in211.1 h108.2° (2024)35.4° (1971)
November74.4°50.5°0.9 in210.2 h95.4° (2020)30.7° (1958)
December65.5°43.6°1.3 in39.8 h85.5° (1950)20.0° (1968)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +4.4°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: +0.57°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: +0.64°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: 170.9 early in the record → 192.5 recently. Frost days: 6 → 0.

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 1995, coldest in 1968: 119.4°F / 20.0°F.

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

Annual rainfall

~9.9 in/year on average. Last decade: −1% vs that average. Long-term trend: +0.22 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 Deer Valley

Which is the warmest month in Deer Valley?
On long-term average, the warmest month in Deer Valley is July (mean daily temperature of about 93.6°F) and the coolest is January (about 52.6°F).
How does today's temperature in Deer Valley compare to the historical average?
On October 26, 2026, Deer Valley is forecast to reach a high of 79.5°F and a low of 55.2°F. The long-term average for this date (the full record since 1940) is a high of 83.4°F and a low of 57.9°F, so today's high is 3.9°F cooler than that average.
How much has Deer Valley warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Deer Valley is about 4.4°F warmer.
How much does it rain in Deer Valley?
Deer Valley receives about 9.9 inches of precipitation per year on long-term average, with January typically the wettest month.
What is the average temperature in Deer Valley?
Over the full record (since 1940), the annual mean temperature in Deer Valley is about 72.5°F. The warmest month is July and the coolest is January.
What are the average temperatures in Deer Valley by month?
Average daily highs and lows for each month in Deer Valley (°F, full record since 1940): January 65°/43°, February 69°/46°, March 75°/50°, April 84°/57°, May 92°/65°, June 102°/74°, July 105°/82°, August 103°/81°, September 98°/74°, October 87°/62°, November 74°/51°, December 66°/44°.
What is the weather like in Deer Valley in summer?
Summer in Deer Valley (June to August) is dry and really hot. Afternoons run 102–105°F and nights 74–82°F; July is the warmest month. Rain rises from 0.1 inches in June to 1.0 inches in August.
What is the weather like in Deer Valley in winter?
December to February is winter in Deer Valley, and it is mild. Expect 65–69°F by day and 43–46°F at night, with January the coldest month. Rain is steady at around 1.3 inches a month, spread over roughly 3 days. It is the wettest season of the year.
What is the weather like in Deer Valley in spring?
In spring, March through May, Deer Valley is dry and warm. It warms from 75°F by day and 50°F at night in March to 92°F and 65°F in May. Rain eases through the season, 1.2 inches in March to 0.1 inches in May.
What is the weather like in Deer Valley in autumn?
Autumn in Deer Valley (September to November) is hot. It cools from 98°F by day and 74°F at night in September to 74°F and 51°F in November. Rain is steady at around 0.8 inches a month, spread over roughly 2 days.
How many days a year does it rain in Deer Valley?
On long-term average, Deer Valley has about 23 days a year with at least 0.08 inches of rain or snow. The annual total is roughly 9.9 inches.

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