Boulder
United States · 9 June 2018
Average
17.2°C
low 10.2°C · high 26.5°C
Rainfall
1.2mm
rain recorded
Wind
3.3m/s
daily average
Humidity
61.7%
daily average
Cloud
34%
cover
Pressure
1004hPa
daily average
The temperature ranged from 10.2°C around 06:00 to 26.5°C around 15:00. Rain was recorded across 2 hours, from around 18:00 to 20:00 (1.2mm total).
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
90th percentile
Low temperature
86th percentile
Rainfall
57th percentile
Wind
91th percentile
A percentile of 100 means this was the hottest/wettest/windiest of the comparable days on file; 50 is right in the middle. This window's average temperature was 13.5°C, versus 17.2°C on this specific day.
Sun & daylight
Sunrise
05:36
Sunset
21:18
Day length
15h 42m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/Denver.
Cumulative rainfall through the day.
| Local time | UTC | Temp | Feels | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 06:00 | 14°C | 13.4°C | 0 | 1.8 | ESE | 90 | 1010 |
| 01:00 | 07:00 | 14.1°C | 13°C | 0 | 2 | SE | 81 | 1010 |
| 02:00 | 08:00 | 13.6°C | 12.4°C | 0 | 1.9 | SE | 82 | 1009 |
| 03:00 | 09:00 | 11°C | 9.5°C | 0 | 1.7 | SSE | 86 | 1009 |
| 04:00 | 10:00 | 11°C | 8.7°C | 0 | 2.2 | S | 74 | 1010 |
| 05:00 | 11:00 | 11.2°C | 9°C | 0 | 2.2 | S | 75 | 1010 |
| 06:00 | 12:00 | 10.2°C | 7.9°C | 0 | 2.2 | SSE | 79 | 1009 |
| 07:00 | 13:00 | 11.4°C | 9.8°C | 0 | 1.6 | SSE | 79 | 1009 |
| 08:00 | 14:00 | 13.4°C | 12°C | 0 | 1.5 | SSE | 72 | 1009 |
| 09:00 | 15:00 | 17.1°C | 15.6°C | 0 | 1.9 | SE | 60 | 1007 |
| 10:00 | 16:00 | 17.9°C | 16°C | 0 | 2.5 | SSE | 58 | 1006 |
| 11:00 | 17:00 | 19.8°C | 17°C | 0 | 3.3 | SSE | 46 | 1004 |
| 12:00 | 18:00 | 21.5°C | 18.1°C | 0 | 4.3 | SSE | 43 | 1002 |
| 13:00 | 19:00 | 23.9°C | 19.8°C | 0.01 | 5.6 | SSE | 39 | 1001 |
| 14:00 | 20:00 | 25.2°C | 19.6°C | 0 | 6.8 | S | 30 | 999 |
| 15:00 | 21:00 | 26.5°C | 19.4°C | 0 | 7.6 | S | 20 | 997 |
| 16:00 | 22:00 | 25.1°C | 19.7°C | 0.02 | 5.8 | S | 26 | 997 |
| 17:00 | 23:00 | 25°C | 20°C | 0.02 | 5.9 | SSW | 31 | 997 |
| 18:00 | 00:00 | 22.5°C | 19.3°C | 0.7 | 4 | SSW | 41 | 999 |
| 19:00 | 01:00 | 22.2°C | 21.8°C | 0 | 1.4 | WSW | 51 | 999 |
| 20:00 | 02:00 | 20.2°C | 18.7°C | 0.43 | 3.1 | NW | 61 | 999 |
| 21:00 | 03:00 | 13.7°C | 11.5°C | 0.04 | 3.5 | NW | 81 | 1001 |
| 22:00 | 04:00 | 12.3°C | 10.1°C | 0 | 3.1 | NNW | 85 | 1001 |
| 23:00 | 05:00 | 11.1°C | 8.8°C | 0 | 3.3 | NW | 91 | 1002 |
Nearby cities
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Data 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
- Boulder — 46.250°, -112.000°, ERA5 grid cell center, 9.4 km from requested point
- Time zone
- America/Denver
- What's shown here
- The hourly and daily record for 9 June 2018 specifically — not a monthly average. See the Boulder climate overview for typical conditions.
- 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 (2026-07-21). Historical climate data for Boulder, United States (46.25°N, 112.00°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Boulder, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 21, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Boulder, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 21, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Boulder, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-21},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.