Meridian Weather in September (1981–2025)

📍 43.61°N, 116.42°W •
📊

September at a Glance in Meridian

(1981–2025)
Avg High
🔥
26.0°C
Avg Low
❄️
11.4°C
Avg Temp
🌡️
18.7°C
Avg Rain
🌧️
16 mm
Avg Humidity
💧
35%
Avg Wind
🌬️
2 m/s
Avg Solar
☀️
5.2
kWh/m²/day
vs Annual
📈
+8.1°C
temp difference
🌡️Warm afternoons🌤️Cool mornings☀️Very sunny💧Dry month🍃Light winds🏜️Low humidity

Meridian September Weather Overview

September is one of the warmer months of the year in Meridian, with average highs near 26°C and lows around 11.4°C (mean 18.7°C). It is one of the drier months, averaging 16 mm of rainfall and 35% relative humidity across the period.

Meridian September Temperature History (1981–2025)

Range

September is one of the warmer months of the year in Meridian. Across 45 years of records, the warmest September in Meridian was 2022 — when the month averaged 22.1°C — while the coldest was 1985 at 13.2°C. Typical September days reach 26°C with nights near 11.4°C. The long-term trend is warming, about 0.7°C per decade.

1981–1985 vs 2021–2025

Avg Temp16.2°C→20.5°C+4.3°C
Max Temp23.4°C→27.9°C+4.5°C
Min Temp9.0°C→13.2°C+4.2°C

Trend (per decade)

Avg Temp+0.7°C/decade ↗
Max Temp+0.7°C/decade ↗
Min Temp+0.8°C/decade ↗

Distribution of Avg Temp

13.0°C–15.5°C2 yr (4%)
15.5°C–18.0°C14 yr (31%)
18.0°C–20.5°C19 yr (42%)
20.5°C–23.0°C10 yr (22%)

Meridian September Rainfall History (1981–2025)

Range

September is one of the drier months in Meridian, averaging 16 mm of rainfall. The wettest September on record was 1986 with 71 mm, while the driest was 1987 at 0 mm.

Meridian September Humidity History (1981–2025)

Range

Relative humidity in Meridian during September averages 35%. The most humid September was 1986 at 53%, and the least humid was 1987 at 23%.

Meridian September Solar History (1981–2025)

Range

September receives about 5.2 kWh/m²/day of solar energy in Meridian. The sunniest Septembers were 1990, 1993 and 1999 at 5.7 kWh/m²/day, and the cloudiest was 1986 at 4.4.

Meridian September Wind History (1981–2025)

Range

Average wind speed in Meridian during September is 2 m/s. The windiest Septembers were 2007 and 2013 at 2.3 m/s, while the calmest was 1998 at 1.6 m/s.

What September Feels Like in Meridian

🌅
Cool
Morning
🌞
Warm
Afternoon
🌆
Cool
Evening
Rain chanceLow
Outdoor comfort★★★★★

How September Ranks in Meridian

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

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

Explore Meridian Weather by Month

Meridian September Averages by Decade

Metric1980s1990s2000s2010s2020sChange
Avg Temp16.7°C18.9°C18.6°C19.2°C20.6°C+3.9°C
Avg High23.9°C26.3°C26.1°C26.3°C28.0°C+4.1°C
Avg Low9.4°C11.5°C11.2°C12.1°C13.2°C+3.8°C
Avg Rain26 mm10 mm12 mm17 mm15 mm-11 mm

Extreme September Records in Meridian

🔥Warmest September40.2°C2022
🧊Coldest September-1.2°C1985
🌧️Wettest September71 mm1986
🏜️Driest September0 mm1987
🌬️Windiest September2.3 m/s2007

Key Insights for September

✅

September temperatures in Meridian have risen by about 4.3°C between 1981–1985 and 2021–2025.

✅

September has ranged from a record low of -1.2°C (1985) to a record high of 40.2°C (2022).

✅

Rainfall in September is one of the drier months, averaging 16 mm, with a wettest year of 71 mm.

Is September a Good Time to Visit Meridian?

One of the best times to visit Meridian

September is one of the best times to visit Meridian. Expect days averaging 26°C and nights around 11.4°C (mean 18.7°C) — warmer than Meridian's yearly average — with low rainfall (16 mm), so conditions are generally comfortable for sightseeing and outdoor plans.

See Meridian'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 →

Meridian Weather in September — In Depth

☀️ September climate overview

September is one of the warmer months of the year in Meridian, with average highs near 26°C and lows around 11.4°C (mean 18.7°C). It is one of the drier months, averaging 16 mm of rainfall and 35% relative humidity across the period.

🌧️ Rain, humidity & wind in September

September averages 16 mm of rainfall in Meridian, one of the drier months compared with the rest of the year. The wettest September on record saw 71 mm (1986), and the driest just 0 mm (1987). Humidity sits around 35% and average wind speed is 2 m/s, with solar radiation averaging 5.2 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 4.3°C. Daytime highs moved from 23.4°C to 27.9°C and overnight lows from 9°C to 13.2°C over the same span.
September Weather in Meridian, Year by Year
🔥 warmest❄️ coldest🌧️ wettest
YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfallHumidityWindSolar
202528.6°C21.4°C14.3°C37.0°C8.7°C23 mm38%1.8 m/s5
202428.2°C20.8°C13.4°C36.8°C4.3°C17 mm36%1.9 m/s5
202326.0°C19.1°C12.1°C32.5°C5.4°C19 mm41%1.9 m/s5
2022 🔥29.7°C22.1°C14.6°C40.2°C9.3°C10 mm30%1.9 m/s5.2
202127.1°C19.3°C11.5°C36.5°C5.0°C17 mm32%2 m/s5.2
202028.2°C20.6°C13.1°C37.5°C6.3°C6 mm29%1.9 m/s5.1
201924.4°C17.8°C11.3°C36.6°C0.9°C27 mm46%2 m/s4.8
201826.1°C18.8°C11.5°C35.5°C4.5°C1 mm28%2 m/s5.4
201725.2°C18.6°C12.0°C38.5°C2.2°C28 mm40%1.8 m/s4.7
201624.5°C17.6°C10.7°C31.5°C6.7°C16 mm39%2.2 m/s5
201526.7°C19.5°C12.3°C34.6°C6.2°C20 mm36%1.7 m/s5.1
201427.3°C20.1°C12.8°C34.4°C5.7°C27 mm36%2 m/s5.2
201324.5°C18.5°C12.4°C35.7°C1.6°C47 mm49%2.3 m/s4.5
201228.2°C20.6°C12.9°C33.0°C6.0°C1 mm26%1.9 m/s5.3
201129.4°C21.6°C13.9°C34.8°C8.1°C4 mm29%1.8 m/s5.6
201026.6°C19.1°C11.5°C33.4°C5.5°C3 mm33%1.9 m/s5.4
200928.4°C20.8°C13.2°C34.0°C2.9°C2 mm30%2.1 m/s5.5
200826.1°C18.6°C11.0°C32.9°C4.9°C20 mm31%1.9 m/s5.5
200725.0°C17.6°C10.3°C38.4°C1.8°C25 mm36%2.3 m/s5.2
200625.7°C18.4°C11.1°C37.1°C3.3°C9 mm32%2 m/s5.2
200525.1°C17.6°C10.1°C35.5°C3.7°C8 mm33%1.8 m/s5.5
200424.6°C17.4°C10.3°C33.3°C3.3°C12 mm42%2.1 m/s5.2
200326.7°C19.3°C12.0°C35.3°C4.9°C2 mm30%2 m/s5.3
200226.3°C18.8°C11.2°C35.0°C3.7°C8 mm31%2 m/s5.3
200128.6°C20.7°C12.9°C34.8°C7.0°C11 mm30%2 m/s5.4
200024.6°C17.2°C9.9°C37.3°C1.3°C18 mm39%2.2 m/s5
199925.8°C18.0°C10.2°C32.6°C-0.4°C1 mm25%2.1 m/s5.7
199827.5°C20.6°C13.7°C38.2°C6.0°C30 mm42%1.6 m/s5.2
199726.6°C19.3°C12.1°C34.8°C4.5°C20 mm40%2 m/s5.1
199623.5°C16.5°C9.4°C34.2°C3.1°C14 mm38%2.1 m/s5.1
199526.3°C19.2°C12.0°C36.1°C4.1°C6 mm35%2 m/s5.4
199427.9°C20.2°C12.6°C35.0°C7.4°C6 mm27%1.9 m/s5.4
199325.2°C17.6°C9.9°C33.7°C2.0°C1 mm33%1.9 m/s5.7
199224.8°C17.4°C10.0°C33.9°C4.3°C6 mm33%2.2 m/s5
199125.9°C18.8°C11.7°C33.1°C3.3°C17 mm37%1.8 m/s5.4
199029.9°C21.7°C13.5°C35.9°C8.6°C3 mm30%1.8 m/s5.7
198925.3°C17.5°C9.8°C30.8°C4.6°C26 mm37%1.9 m/s5.6
198825.0°C17.4°C9.9°C37.4°C1.6°C8 mm30%2.1 m/s5.3
198727.6°C19.9°C12.2°C36.9°C5.0°C0 mm23%1.8 m/s5.6
1986 🌧️19.8°C14.0°C8.2°C33.9°C1.7°C71 mm53%1.8 m/s4.4
1985 ❄️19.9°C13.2°C6.4°C27.5°C-1.2°C59 mm50%2 m/s4.8
198423.8°C16.2°C8.6°C34.0°C-0.7°C14 mm39%2 m/s5.1
198323.9°C16.4°C8.9°C32.4°C0.3°C15 mm41%2.2 m/s—
198223.3°C16.4°C9.4°C34.6°C0.7°C36 mm47%2.2 m/s—
198126.2°C18.9°C11.5°C36.2°C3.3°C8 mm32%2 m/s—

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

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Meridian September Weather — FAQ

What is the average temperature in Meridian in September?▼

The average high in September is around 26°C with lows near 11.4°C (mean 18.7°C), based on 45 years of NASA POWER data.

Does it rain a lot in Meridian in September?▼

September averages 16 mm of rainfall in Meridian, one of the drier months. The wettest on record was 71 mm in 1986.

What was the hottest September on record in Meridian?▼

The hottest September reached 40.2°C in 2022. The coldest dipped to -1.2°C in 1985.

Has September in Meridian 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 4.3°C. Daytime highs moved from 23.4°C to 27.9°C and overnight lows from 9°C to 13.2°C over the same span.

Is September a good time to visit Meridian?▼

September is one of the warmer months of the year in Meridian and one of the drier months, so plan for around 26°C daytime highs and 11.4°C at night.

Is September the coldest month in Meridian?▼

Not quite — September is the 9th coolest month in Meridian, averaging 18.7°C.

What should I pack for Meridian in September?▼

For September in Meridian, pack light layers you can adjust through the day, with typical highs of 26°C and lows of 11.4°C.

Is Meridian humid in September?▼

Relative humidity in September averages 35% — relatively dry.

How windy is Meridian in September?▼

Average wind speed in September is 2 m/s. The windiest September on record averaged 2.3 m/s (2007).

Which September had the most rainfall in Meridian?▼

The wettest September on record was 1986 with 71 mm. On average, September sees 16 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 Idaho cities

Explore how the weather in Meridian 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.