Orange Weather in September (1981–2025)

📍 33.80°N, 117.83°W •
📊

September at a Glance in Orange

(1981–2025)
Avg High
🔥
29.6°C
Avg Low
❄️
17.6°C
Avg Temp
🌡️
23.6°C
Avg Rain
🌧️
6 mm
Avg Humidity
💧
51%
Avg Wind
🌬️
1.8 m/s
Avg Solar
☀️
5.8
kWh/m²/day
vs Annual
📈
+5.7°C
temp difference
🌡️Warm afternoons🌤️Cool mornings☀️Very sunny💧Dry month🍃Light winds🏜️Low humidity

Orange September Weather Overview

September is one of the warmer months of the year in Orange, with average highs near 29.6°C and lows around 17.6°C (mean 23.6°C). It is one of the drier months, averaging 6 mm of rainfall and 51% relative humidity across the period.

Orange September Temperature History (1981–2025)

Range

September is one of the warmer months of the year in Orange. Across 45 years of records, the warmest September in Orange was 1984 — when the month averaged 26.6°C — while the coldest was 1986 at 19.7°C. Typical September days reach 29.6°C with nights near 17.6°C. The long-term trend is warming, about 0.2°C per decade.

1981–1985 vs 2021–2025

Avg Temp23.7°C→23.8°C+0.1°C
Max Temp29.5°C→29.4°C-0.1°C
Min Temp17.8°C→18.2°C+0.4°C

Trend (per decade)

Avg Temp+0.2°C/decade ↗
Max Temp+0.2°C/decade ↗
Min Temp+0.3°C/decade ↗

Distribution of Avg Temp

19.0°C–21.0°C1 yr (2%)
21.0°C–23.0°C8 yr (18%)
23.0°C–25.0°C29 yr (64%)
25.0°C–27.0°C7 yr (16%)

Orange September Rainfall History (1981–2025)

Range

September is one of the drier months in Orange, averaging 6 mm of rainfall. The wettest September on record was 1983 with 52 mm, while the driest were 2009, 2018 and 2020, among others at 0 mm.

Orange September Humidity History (1981–2025)

Range

Relative humidity in Orange during September averages 51%. The most humid September was 2023 at 69%, and the least humid was 2020 at 42%.

Orange September Solar History (1981–2025)

Range

September receives about 5.8 kWh/m²/day of solar energy in Orange. The sunniest September was 2014 at 6.3 kWh/m²/day, and the cloudiest was 2023 at 5.1.

Orange September Wind History (1981–2025)

Range

Average wind speed in Orange during September is 1.8 m/s. The windiest Septembers were 1985 and 1986 at 2.1 m/s, while the calmest were 1991 and 2020 at 1.5 m/s.

What September Feels Like in Orange

🌅
Cool
Morning
🌞
Warm
Afternoon
🌆
Mild
Evening
Rain chanceVery Low
Outdoor comfort★★★★★

How September Ranks in Orange

🔥3rd warmest month of the year
🌵4th driest month of the year
☀️6th sunniest month of the year

Ranked against the other 11 months using 1981–2025 averages.

Explore Orange Weather by Month

Orange September Averages by Decade

Metric1980s1990s2000s2010s2020sChange
Avg Temp23.1°C23.4°C23.5°C23.9°C24.1°C+1°C
Avg High29.2°C29.4°C29.8°C29.9°C29.9°C+0.7°C
Avg Low17.1°C17.5°C17.3°C17.9°C18.4°C+1.3°C
Avg Rain16 mm3 mm3 mm4 mm5 mm-12 mm

Extreme September Records in Orange

🔥Warmest September41.5°C2020
🧊Coldest September9.0°C1982
🌧️Wettest September52 mm1983
🏜️Driest September0 mm1992
🌬️Windiest September2.1 m/s1985

Key Insights for September

✅

September temperatures in Orange have stayed relatively stable across the record.

✅

September has ranged from a record low of 9°C (1982) to a record high of 41.5°C (2020).

✅

Rainfall in September is one of the drier months, averaging 6 mm, with a wettest year of 52 mm.

Is September a Good Time to Visit Orange?

One of the best times to visit Orange

September is one of the best times to visit Orange. Expect days averaging 29.6°C and nights around 17.6°C (mean 23.6°C) — warmer than Orange's yearly average — with low rainfall (6 mm), so conditions are generally comfortable for sightseeing and outdoor plans.

See Orange's complete weather history All 12 months side by side, 1981–2025 records, annual trends and long-term averages in one place. View full history →

Orange Weather in September — In Depth

☀️ September climate overview

September is one of the warmer months of the year in Orange, with average highs near 29.6°C and lows around 17.6°C (mean 23.6°C). It is one of the drier months, averaging 6 mm of rainfall and 51% relative humidity across the period.

🌧️ Rain, humidity & wind in September

September averages 6 mm of rainfall in Orange, one of the drier months compared with the rest of the year. The wettest September on record saw 52 mm (1983), and the driest just 0 mm (1992). Humidity sits around 51% and average wind speed is 1.8 m/s, with solar radiation averaging 5.8 kWh/m²/day.

📈 How September has changed

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.1°C — but days and nights have moved in opposite directions. Overnight lows rose from 17.8°C to 18.2°C while daytime highs eased from 29.5°C to 29.4°C, narrowing the gap between day and night.
September Weather in Orange, Year by Year
🔥 warmest❄️ coldest🌧️ wettest
YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfallHumidityWindSolar
202529.1°C23.8°C18.6°C35.2°C16.1°C7 mm62%1.8 m/s5.7
202430.1°C24.2°C18.3°C40.0°C13.4°C1 mm51%1.8 m/s5.8
202326.8°C21.8°C16.8°C32.4°C13.8°C4 mm69%1.9 m/s5.1
202231.4°C25.7°C20.1°C38.1°C15.0°C14 mm55%1.9 m/s5.7
202129.5°C23.4°C17.4°C35.2°C12.5°C1 mm50%1.6 m/s5.9
202032.3°C25.8°C19.2°C41.5°C14.8°C0 mm42%1.5 m/s5.9
201929.7°C23.8°C17.9°C35.5°C11.1°C1 mm53%1.8 m/s6
201829.4°C23.2°C17.0°C33.6°C14.2°C0 mm52%1.7 m/s6.1
201728.9°C23.2°C17.5°C39.9°C12.1°C4 mm57%2 m/s5.7
201629.2°C23.0°C16.8°C36.6°C13.0°C1 mm50%1.8 m/s5.9
201530.6°C25.0°C19.5°C37.0°C14.7°C29 mm56%1.7 m/s6
201430.9°C25.0°C19.1°C38.3°C14.2°C1 mm51%1.7 m/s6.3
201329.8°C23.6°C17.5°C36.2°C11.4°C1 mm47%1.8 m/s6.1
201231.5°C25.5°C19.6°C37.4°C14.8°C1 mm43%1.7 m/s6.1
201129.3°C23.2°C17.1°C37.0°C13.6°C2 mm49%1.6 m/s5.5
201029.7°C23.2°C16.7°C40.2°C11.3°C1 mm45%1.7 m/s5.9
200931.3°C24.9°C18.5°C37.1°C11.3°C0 mm48%1.7 m/s6.2
200830.5°C24.3°C18.1°C34.7°C13.9°C0 mm51%1.8 m/s5.9
200727.9°C22.1°C16.3°C39.2°C12.1°C14 mm55%1.9 m/s6.1
200629.6°C23.3°C17.0°C35.8°C11.1°C1 mm45%1.7 m/s6.1
200527.8°C21.7°C15.7°C35.2°C11.4°C6 mm52%1.7 m/s6.1
200430.2°C23.9°C17.5°C35.6°C12.2°C0 mm50%1.9 m/s6.2
200330.7°C24.2°C17.8°C34.5°C14.6°C0 mm51%1.6 m/s5.8
200230.2°C24.0°C17.8°C37.7°C13.6°C1 mm46%1.8 m/s5.6
200129.7°C23.5°C17.3°C35.2°C14.1°C1 mm52%1.6 m/s5.9
200029.6°C23.3°C17.1°C37.6°C13.8°C5 mm51%1.9 m/s5.7
199928.4°C22.3°C16.2°C36.6°C12.9°C1 mm54%1.7 m/s5.7
199827.5°C22.3°C17.1°C37.1°C13.2°C10 mm62%1.9 m/s5.4
199731.2°C25.3°C19.5°C35.1°C15.6°C16 mm51%1.8 m/s5.8
199628.3°C22.4°C16.5°C32.3°C13.5°C0 mm57%1.8 m/s5.8
199530.3°C24.3°C18.3°C34.3°C11.7°C0 mm47%1.8 m/s6
199428.9°C23.0°C17.1°C32.9°C12.8°C1 mm51%1.8 m/s5.7
199329.5°C23.1°C16.7°C36.3°C10.6°C0 mm46%1.8 m/s5.6
199230.6°C24.4°C18.1°C34.8°C13.4°C0 mm46%1.7 m/s6
199129.1°C23.4°C17.7°C34.5°C12.8°C2 mm53%1.5 m/s5.5
199030.1°C23.8°C17.6°C36.5°C13.8°C1 mm48%1.8 m/s6
198929.6°C23.2°C16.7°C34.5°C11.6°C12 mm44%1.9 m/s5.9
198829.9°C23.4°C16.9°C40.5°C12.5°C2 mm48%1.8 m/s5.3
198729.7°C23.4°C17.1°C37.7°C13.4°C3 mm51%1.8 m/s5.5
1986 ❄️25.7°C19.7°C13.7°C33.4°C9.9°C34 mm56%2.1 m/s5.6
198526.7°C21.0°C15.3°C32.5°C12.0°C5 mm55%2.1 m/s5.5
1984 🔥32.5°C26.6°C20.7°C38.7°C15.6°C7 mm48%2 m/s5.3
1983 🌧️30.3°C24.6°C18.9°C36.4°C14.1°C52 mm52%1.8 m/s—
198228.2°C22.6°C16.9°C39.2°C9.0°C24 mm51%1.9 m/s—
198129.9°C23.6°C17.4°C35.7°C13.0°C7 mm43%1.7 m/s—

Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.

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Orange September Weather — FAQ

What is the average temperature in Orange in September?▼

The average high in September is around 29.6°C with lows near 17.6°C (mean 23.6°C), based on 45 years of NASA POWER data.

Does it rain a lot in Orange in September?▼

September averages 6 mm of rainfall in Orange, one of the drier months. The wettest on record was 52 mm in 1983.

What was the hottest September on record in Orange?▼

The hottest September reached 41.5°C in 2020. The coldest dipped to 9°C in 1982.

Has September in Orange gotten warmer over time?▼

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.1°C — but days and nights have moved in opposite directions. Overnight lows rose from 17.8°C to 18.2°C while daytime highs eased from 29.5°C to 29.4°C, narrowing the gap between day and night.

Is September a good time to visit Orange?▼

September is one of the warmer months of the year in Orange and one of the drier months, so plan for around 29.6°C daytime highs and 17.6°C at night.

Is September the coldest month in Orange?▼

Not quite — September is the 10th coolest month in Orange, averaging 23.6°C.

What should I pack for Orange in September?▼

For September in Orange, pack light layers you can adjust through the day, with typical highs of 29.6°C and lows of 17.6°C.

Is Orange humid in September?▼

Relative humidity in September averages 51% — relatively dry.

How windy is Orange in September?▼

Average wind speed in September is 1.8 m/s. The windiest September on record averaged 2.1 m/s (1985).

Which September had the most rainfall in Orange?▼

The wettest September on record was 1983 with 52 mm. On average, September sees 6 mm.

Where does this September weather data come from?▼

All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.

Other California cities

Explore how the weather in Orange behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.