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Glen Carbon climate
Typical historical weather for Glen Carbon, United States, averaged across 10 years of hourly climate data. Pick a date for a specific day.
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Annual average
14.2°C
across all months
Warmest month
30.9°C
Jul average high
Coolest month
-3.9°C
Jan average low
Annual rainfall
1180mm
total per year
Glen Carbon is typically hottest in July and coolest in January, a swing of about 34.8°C across the year. About 34% of annual rainfall falls in the three wettest months (April is typically wettest, December driest).
Monthly averages
Average daily high/low temperature (band) and monthly rainfall (bars).
| Month | Avg high | Avg low | Rainfall | Wet days | Humidity | Wind | Cloud | Solar |
|---|---|---|---|---|---|---|---|---|
| Jan | 4°C · record 9.2–19.5°C | -3.9°C · record -21.5–-10.8°C | 80mm | 9 | 72% | 3.5 m/s | 65% | 2.2 kWh/m² |
| Feb | 7.9°C · record 16.7–27.6°C | -1.9°C · record -18.5–-8.6°C | 72mm | 9 | 67% | 3.6 m/s | 61% | 3.1 kWh/m² |
| Mar | 14.1°C · record 20–27.8°C | 4°C · record -17.2–-1.8°C | 124mm | 12 | 63% | 3.8 m/s | 61% | 4.1 kWh/m² |
| Apr | 19.3°C · record 28.2–31.1°C | 8.4°C · record -4.4–4°C | 141mm | 12 | 61% | 3.8 m/s | 59% | 5.3 kWh/m² |
| May | 24.7°C · record 30.8–34.8°C | 15°C · record 3.7–12.3°C | 132mm | 14 | 66% | 3.1 m/s | 62% | 5.8 kWh/m² |
| Jun | 30.2°C · record 33.7–37.1°C | 20.2°C · record 12.1–15.6°C | 99mm | 11 | 65% | 2.8 m/s | 52% | 6.7 kWh/m² |
| Jul | 30.9°C · record 34.3–38.2°C | 21.9°C · record 14–20.2°C | 119mm | 12 | 72% | 2.3 m/s | 54% | 6.4 kWh/m² |
| Aug | 29.6°C · record 32.5–38.3°C | 20°C · record 9.7–16.6°C | 114mm | 10 | 73% | 2.4 m/s | 52% | 5.7 kWh/m² |
| Sep | 27.9°C · record 31.4–36°C | 16.4°C · record 5.4–12.6°C | 81mm | 7 | 69% | 2.6 m/s | 43% | 4.9 kWh/m² |
| Oct | 20.9°C · record 27.1–33.9°C | 9.7°C · record -2.9–4.5°C | 84mm | 8 | 68% | 3.3 m/s | 47% | 3.4 kWh/m² |
| Nov | 12.8°C · record 16.2–27.7°C | 2.9°C · record -12.5–-3.1°C | 71mm | 8 | 68% | 3.4 m/s | 51% | 2.5 kWh/m² |
| Dec | 7.7°C · record 16.4–21.9°C | -1°C · record -21.5–-4.3°C | 64mm | 8 | 72% | 3.4 m/s | 61% | 1.9 kWh/m² |
"Avg high"/"Avg low" is the mean daily high/low for that month, averaged across every year on file. The "record" figure alongside it is a different statistic — the single hottest (or coldest) hour ever recorded during that month across all years — so it can sit above or below the average and does not describe the average's year-to-year spread. A "wet day" is any day with at least 1.0mm of rain.
Year to year
Annual average temperature, 2016–2025.
Across these 10 years, the annual average has moved by about +0.17°C per decade. That’s a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
Annual rainfall has moved by about -183.68mm per decade over the same period.
2025 (the most recent year on file) averaged 14.046308031474096°C, below the 9-year baseline of 14.22°C by 0.29 standard deviations.
Typical extremes per year
Rainy days
120.5 days
≥1.0mm rain
Heavy rain days
15.2 days
≥20mm rain
Extreme heat days
0 days
daily high ≥40°C
Frost days
74.6 days
daily low ≤0°C
Averaged across 10 years on file. Thresholds match PastClimate's data pipeline definitions — see data & sources.
Records on file
Ranked across 10 years of data currently on file (2016–2025).
Hottest day
38.3°C
25 August 2023
2023 was 1.48 SD above the 9-year average that year
Coldest day
-21.5°C
1 January 2018
2018 was 1.14 SD below the 9-year average that year
Wettest day
114.4mm
26 April 2017
2017 was 1.18 SD above the 9-year average that year
Windiest day
8m/s
14 March 2019
2019 was 1.63 SD below the 9-year average that year
See the detail: Glen Carbon on 26 April 2017.
Nearby cities
Edwardsville
Same ERA5 grid cell
Collinsville
Same ERA5 grid cell
Wood River
Same ERA5 grid cell
Troy
Same ERA5 grid cell
Maryville
Same ERA5 grid cell
Pontoon Beach
Same ERA5 grid cell
Want a side-by-side view instead? Compare Glen Carbon with another city.
Frequently asked questions about Glen Carbon's climate
What is the hottest month in Glen Carbon?
July is typically the warmest month in Glen Carbon, with an average high of 30.9°C. January is typically the coolest, averaging -3.9°C overnight.
How much does it rain in Glen Carbon?
Glen Carbon gets about 1180mm of rain a year on average, with roughly 34% of it falling in the three wettest months (April is typically the wettest, December the driest).
How many extremely hot or cold days does Glen Carbon have?
On average, Glen Carbon sees about 0 day(s) a year at or above 40°C and about 74.6 day(s) at or below 0°C, based on 10 years of data.
Is Glen Carbon getting warmer?
Across the 10 years on file (2016–2025), the annual average temperature has moved by about +0.17°C per decade. That's a short window for a reliable long-term climate trend — treat it as indicative, not definitive.
What is the hottest day on record for Glen Carbon?
The hottest day on file is 25 August 2023 at 38.3°C, out of 10 year(s) searched.
Data & provenance
↓ Download monthly CSVData source & coverage — ERA5 reanalysis, 2016–2025 (10 years)details
- Source
- ERA5 reanalysis, accessed via the Copernicus Climate Change Service (C3S) Climate Data Store
- Data type
- Reanalysis — a physically consistent reconstruction combining a forecast model with historical observations, not a live station reading or a forecast
- Coverage
- 2016–2025 (10 years) for United States
- Location
- Glen Carbon — 38.750°, -90.000°, ERA5 grid cell center, 1.5 km from requested point
- Time zone
- America/Chicago
- What's shown here
- Monthly and annual averages, and dated extreme-value records, derived from an hourly base record.
- Spatial resolution
- 0.25° (~25 km) distributed grid — ERA5's native model resolution is finer; this is the publicly distributed regridded product
- Version / refreshed
- Methodology v2026.07 · data last refreshed December 31, 2025
- Limitations
- A model reconstruction, not a station observation — hyper-local extremes (a single storm cell, an urban heat pocket) can differ from a nearby gauge. See the full methodology.
- Attribution
- Generated using Copernicus Climate Change Service information
Cite this data
PastClimate (2026-07-18). Historical climate data for Glen Carbon, United States (38.75°N, 90.00°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Glen Carbon, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 18, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Glen Carbon, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 18, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Glen Carbon, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-18},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.