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Santa Ana weather by month: averages, rainfall & climate trends

Santa Ana has well-marked seasons, with 18.8°F between its warmest and coolest monthly means. Rainfall is on the low side overall. Santa Ana weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+1.6°Fhigh near average

79° / 65°Today
78° / 60°Average
see today in detail →

How it's changed

+3.1°Faverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4952days above 86°F a year now (2016–2025) · 55 in the 1940sdays above 86°F · 55 in the 1940s+3.1°F vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 3.0 incheshigh 66°low 48°February, rain 3.2 incheshigh 67°low 49°March, rain 2.6 incheshigh 68°low 52°April, rain 1.2 incheshigh 71°low 54°May, rain 0.4 incheshigh 73°low 58°June, rain 0.1 incheshigh 78°low 62°July, rain 0.1 incheshigh 83°low 66°August, rain 0.1 incheshigh 85°low 67°September, rain 0.3 incheshigh 83°low 65°October, rain 0.6 incheshigh 78°low 60°November, rain 1.5 incheshigh 72°low 53°December, rain 2.3 incheshigh 67°low 48°wettest month February, 3.2 inches · 15.4 inches a yearsee month by month →

Right now

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

Right now

76.1°

77°feels like
65%humidity
64°dew point
10 mphfrom SW
UV index3.0
sunrise07:00sunset18:11day length11h 11m
TodayClear79°65°
WedOvercast74°60°
ThuClear71°60°
FriOvercast71°64°
SatClear78°65°
SunClear85°69°
MonClear89°72°

On this date: October 20

Today (forecast)
79° / 65°
Average for October 20
78° / 60°

High near average · +1.6°F

  • Highest since 1940: 96.4° · 2016
  • Lowest since 1940: 48.2° · 1949
  • One year ago: 81° / 59°

Every October 20 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 20 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 Santa Ana is sampled from the ECMWF ERA5 reanalysis at 33.75°N, 117.87°W, with daily records since 1940.

Coordinates
33.75°N, 117.87°W
Time zone
America/Los Angeles
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

28 of the last 31 days were warmer than the historical average for that date. Average difference: +6.3°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 August, at around 84.5°F by mid-afternoon, with nights around 66.8°F. Roughly 50 days a year now top 86°F. At the other extreme, January brings afternoon highs of about 65.8°F and typical overnight lows of 47.6°F. Frost is essentially unknown.

In total, Santa Ana averages about 15.4 inches of precipitation a year; February is usually the wettest month (3.2 inches) and July the driest (0.1 inches).

Over the full record (since 1940), the annual mean temperature in Santa Ana has risen by 3.1°F between its first decade and its last. You can follow the shift year by year in the charts below.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 19°F. Wettest month: February (~3.2 in). Whole year averages ~15.4 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 30 rainy days a year: most in March (~5), fewest in July (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.

Santa Ana 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
January65.8°47.6°3.0 in510.0 h89.7° (2021)29.4° (1949)
February66.7°49.1°3.2 in510.8 h88.8° (2016)35.1° (1949)
March67.8°51.5°2.6 in511.7 h94.3° (1988)38.3° (1966)
April70.8°54.4°1.2 in312.8 h100.6° (1989)42.1° (1999)
May73.4°57.9°0.4 in113.8 h100.1° (2014)46.4° (1950)
June78.0°61.5°0.1 in014.2 h103.4° (2016)51.3° (1953)
July83.5°65.7°0.1 in014.0 h108.0° (2018)55.8° (1948)
August84.5°66.8°0.1 in013.3 h102.0° (1981)58.2° (1949)
September83.4°65.5°0.3 in112.2 h106.4° (1988)53.9° (1948)
October78.4°60.4°0.6 in211.1 h104.0° (1991)41.4° (1971)
November72.1°53.4°1.5 in310.2 h95.9° (2010)38.4° (1957)
December66.5°48.3°2.3 in49.8 h88.7° (1958)31.9° (1978)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +3.1°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: +0.35°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

Dec–Feb is warming fastest: +0.48°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: 55.0 early in the record → 52.4 recently. Frost days: 0 → 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 2018, coldest in 1949: 108.0°F / 29.4°F.

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

Annual rainfall

~15.4 in/year on average. Last decade: +1% vs that average. Long-term trend: −0.07 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 Santa Ana

Which is the warmest month in Santa Ana?
On long-term average, the warmest month in Santa Ana is August (mean daily temperature of about 74.1°F) and the coolest is January (about 55.3°F).
How does today's temperature in Santa Ana compare to the historical average?
On October 20, 2026, Santa Ana is forecast to reach a high of 79.3°F and a low of 64.8°F. The long-term average for this date (the full record since 1940) is a high of 77.7°F and a low of 59.8°F, so today's high is 1.6°F warmer than that average.
How much has Santa Ana warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Santa Ana is about 3.1°F warmer.
How much does it rain in Santa Ana?
Santa Ana receives about 15.4 inches of precipitation per year on long-term average, with February typically the wettest month.
What is the average temperature in Santa Ana?
Over the full record (since 1940), the annual mean temperature in Santa Ana is about 64.2°F. The warmest month is August and the coolest is January.
What are the average temperatures in Santa Ana by month?
Average daily highs and lows for each month in Santa Ana (°F, full record since 1940): January 66°/48°, February 67°/49°, March 68°/52°, April 71°/54°, May 73°/58°, June 78°/62°, July 83°/66°, August 85°/67°, September 83°/65°, October 78°/60°, November 72°/53°, December 67°/48°.
What is the weather like in Santa Ana in summer?
June to August is summer in Santa Ana, and it is dry and warm. Daytime highs sit at 78–85°F and nights at 62–67°F; August is the warmest month. Almost no rain.
What is the weather like in Santa Ana in winter?
Winter in Santa Ana (December to February) is mild. Afternoons run 66–67°F and nights 48–49°F; January is the coldest month. Rain is steady at around 2.8 inches a month, spread over roughly 5 days. No season is wetter.
What is the weather like in Santa Ana in spring?
Spring in Santa Ana (March to May) is mild. Expect 68–73°F by day and 52–58°F at night, with May the warmest month. Rain falls off from 2.6 inches on 5 days in March to 0.4 inches on 1 day in May.
What is the weather like in Santa Ana in autumn?
September to November is autumn in Santa Ana, and it is pleasantly warm. September still brings 83°F afternoons and 65°F nights, November only 72°F and 53°F. Rain picks up through the season: 1 rainy day and 0.3 inches in September, 3 days and 1.5 inches in November.
How many days a year does it rain in Santa Ana?
On long-term average, Santa Ana has about 30 days a year with at least 0.08 inches of rain or snow. The annual total is roughly 15.4 inches.

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