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Downey weather by month: averages, rainfall & climate trends

Downey has well-marked seasons, with 20.6°F between its warmest and coolest monthly means. This is a dry climate by most measures, though not a rainless one. Downey weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

+13.8°Fhigh well above average

95° / 73°Today
81° / 59°Average
see today in detail →

How it's changed

+3.2°Faverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4985days above 86°F a year now (2016–2025) · 84 in the 1940sdays above 86°F · 84 in the 1940s+3.2°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 46°February, rain 3.1 incheshigh 68°low 48°March, rain 2.5 incheshigh 70°low 50°April, rain 1.1 incheshigh 74°low 53°May, rain 0.3 incheshigh 77°low 57°June, rain 0.1 incheshigh 81°low 60°July, rain 0.05 incheshigh 87°low 65°August, rain 0.1 incheshigh 88°low 66°September, rain 0.2 incheshigh 87°low 64°October, rain 0.5 incheshigh 81°low 59°November, rain 1.4 incheshigh 74°low 52°December, rain 2.2 incheshigh 67°low 47°wettest month February, 3.1 inches · 14.5 inches a yearsee month by month →

Right now

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

Right now

75.0°

70°feels like
30%humidity
41°dew point
8 mphfrom NE
UV index0.0
sunrise06:59sunset18:16day length11h 17m
TodayOvercast95°73°
SunClear90°66°
MonClear82°72°
TueClear77°68°
WedDrizzle70°63°
ThuDrizzle72°64°
FriClear74°65°

On this date: October 17

Today (forecast)
95° / 73°
Average for October 17
81° / 59°

High well above average · +13.8°F

  • Record high: 99.5° · 1958
  • Record low: 48.8° · 1946
  • One year ago: 82° / 55°

Every October 17 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 17 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 Downey is sampled from the ECMWF ERA5 reanalysis at 33.94°N, 118.13°W, with daily records since 1940.

Coordinates
33.94°N, 118.13°W
Time zone
America/Los Angeles
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

27 of the last 31 days were warmer than the historical average for that date. Average difference: +5.5°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

August brings the year's peak warmth, with afternoons typically reaching 88.2°F and nights around 65.5°F. Roughly 85 days a year now top 86°F. At the other extreme, January brings afternoon highs of about 66.5°F and typical overnight lows of 46.1°F. Frost is essentially unknown.

Downey picks up roughly 14.5 inches a year, with a peak of 3.1 inches in February and as little as 0.05 inches in July.

The record here starts in 1940, and since then the annual mean in Downey has climbed 3.2°F from the first ten years to the last ten. The year-by-year charts below trace that shift in detail.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 21°F. Wettest month: February (~3.1 in). Whole year averages ~14.5 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 26 rainy days a year: most in February (~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.

Downey 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. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightRecord highRecord low
January66.5°46.1°3.0 in510.0 h90.1° (2003)28.7° (1949)
February67.8°47.7°3.1 in510.8 h90.8° (2016)30.6° (1990)
March69.8°50.1°2.5 in511.7 h98.0° (1988)33.5° (1945)
April73.8°53.1°1.1 in212.9 h104.9° (1989)38.2° (1945)
May76.7°56.7°0.3 in113.8 h108.6° (1984)45.6° (1964)
June81.4°60.4°0.1 in014.2 h113.2° (1990)48.6° (1950)
July87.2°64.6°0.05 in014.1 h114.1° (2018)54.4° (1948)
August88.2°65.5°0.1 in013.3 h108.5° (1997)56.0° (1947)
September86.6°64.1°0.2 in012.2 h113.4° (2020)50.9° (1948)
October80.9°58.9°0.5 in111.1 h107.9° (1991)39.2° (1971)
November73.5°51.6°1.4 in310.2 h98.0° (2010)35.1° (1964)
December67.1°46.5°2.2 in49.8 h89.8° (1958)28.3° (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 +3.2°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

Dec–Feb is warming fastest: +0.53°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: 83.6 early in the record → 84.7 recently. Frost days: 1 → 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

All-time high in 2018, all-time low in 1978: 114.1°F / 28.3°F.

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

Annual rainfall

~14.5 in/year on average. Last decade: +5% vs that average. Long-term trend: −0.03 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 Downey

Which is the warmest month in Downey?
On long-term average, the warmest month in Downey is August (mean daily temperature of about 75.2°F) and the coolest is January (about 54.6°F).
How does today's temperature in Downey compare to the historical average?
On October 17, 2026, Downey is forecast to reach a high of 94.6°F and a low of 73.2°F. The long-term average for this date (the full record since 1940) is a high of 80.9°F and a low of 59.0°F, so today's high is 13.8°F warmer than that average.
How much has Downey warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Downey is about 3.2°F warmer.
How much does it rain in Downey?
Downey receives about 14.5 inches of precipitation per year on long-term average, with February typically the wettest month.
What is the average temperature in Downey?
Over the full record (since 1940), the annual mean temperature in Downey is about 64.5°F. The warmest month is August and the coolest is January.
What are the average temperatures in Downey by month?
Average daily highs and lows for each month in Downey (°F, full record since 1940): January 66°/46°, February 68°/48°, March 70°/50°, April 74°/53°, May 77°/57°, June 81°/60°, July 87°/65°, August 88°/66°, September 87°/64°, October 81°/59°, November 74°/52°, December 67°/47°.
What is the weather like in Downey in summer?
Summer in Downey (June to August) is dry and warm. June starts at 81°F by day and 60°F at night; by August it is 88°F and 66°F. Almost no rain.
What is the weather like in Downey in winter?
In winter, December through February, Downey is mild. Daytime highs sit at 66–68°F and nights at 46–48°F; January is the coldest month. Rain falls on about 4 days a month, adding up to around 2.8 inches. It is the wettest season of the year.
What is the weather like in Downey in spring?
In spring, March through May, Downey is pleasantly warm. March is still 70°F in the afternoon and 50°F at night, May already 77°F and 57°F. Rain eases through the season: 5 rainy days and 2.5 inches in March, 1 day and 0.3 inches in May.
What is the weather like in Downey in autumn?
Autumn in Downey (September to November) is dry and warm. September is still 87°F by day and 64°F at night; by November it is down to 74°F and 52°F. Rain picks up through the season, 0.2 inches in September to 1.4 inches in November.
How many days a year does it rain in Downey?
On long-term average, Downey has about 26 days a year with at least 0.08 inches of rain or snow. The annual total is roughly 14.5 inches.

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