Boulder
United States · 13 May 2017
Average
16.1°C
low 6.2°C · high 25.3°C
Rainfall
0.4mm
dry day
Wind
2.3m/s
daily average
Humidity
46%
daily average
Cloud
21%
cover
Pressure
1002hPa
daily average
The temperature ranged from 6.2°C around 06:00 to 25.3°C around 15:00. Rain was recorded across 3 hours, from around 16:00 to 18:00 (0.4mm total).
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
93th percentile
Low temperature
80th percentile
Rainfall
31th percentile
Wind
76th 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 10.2°C, versus 16.1°C on this specific day.
Sun & daylight
Sunrise
05:47
Sunset
20:07
Day length
14h 21m
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 | 9.5°C | 6.9°C | 0 | 2.3 | WSW | 76 | 1007 |
| 01:00 | 07:00 | 8°C | 4.9°C | 0 | 2.6 | W | 77 | 1006 |
| 02:00 | 08:00 | 7.1°C | 3.7°C | 0 | 2.8 | W | 76 | 1006 |
| 03:00 | 09:00 | 6.5°C | 2.9°C | 0 | 2.9 | W | 77 | 1005 |
| 04:00 | 10:00 | 6.5°C | 2.9°C | 0 | 2.9 | W | 78 | 1006 |
| 05:00 | 11:00 | 6.4°C | 2.7°C | 0 | 2.9 | W | 75 | 1006 |
| 06:00 | 12:00 | 6.2°C | 2.5°C | 0 | 2.8 | W | 75 | 1006 |
| 07:00 | 13:00 | 7.3°C | 3.7°C | 0 | 3 | W | 76 | 1006 |
| 08:00 | 14:00 | 12.6°C | 10.1°C | 0 | 2.1 | W | 63 | 1006 |
| 09:00 | 15:00 | 18.7°C | 16.3°C | 0 | 0.7 | WSW | 29 | 1005 |
| 10:00 | 16:00 | 20.7°C | 18°C | 0 | 1.3 | SSE | 28 | 1004 |
| 11:00 | 17:00 | 22.4°C | 19.3°C | 0 | 2.1 | SSE | 28 | 1003 |
| 12:00 | 18:00 | 23.2°C | 19.9°C | 0 | 2.5 | SSE | 26 | 1002 |
| 13:00 | 19:00 | 24.2°C | 20.7°C | 0.01 | 2.6 | SSE | 23 | 1000 |
| 14:00 | 20:00 | 24.7°C | 21.1°C | 0 | 2.6 | SSE | 22 | 999 |
| 15:00 | 21:00 | 25.3°C | 21.8°C | 0 | 2.5 | SSE | 20 | 999 |
| 16:00 | 22:00 | 24.1°C | 18.4°C | 0.11 | 5.2 | ESE | 20 | 996 |
| 17:00 | 23:00 | 24.1°C | 21.7°C | 0.14 | 0.4 | SSW | 19 | 998 |
| 18:00 | 00:00 | 23.5°C | 21°C | 0.15 | 1.6 | WNW | 27 | 998 |
| 19:00 | 01:00 | 22.7°C | 20.8°C | 0 | 1.8 | WNW | 37 | 998 |
| 20:00 | 02:00 | 22.2°C | 18.6°C | 0 | 2.3 | W | 23 | 998 |
| 21:00 | 03:00 | 14.8°C | 11.5°C | 0 | 1.8 | W | 37 | 999 |
| 22:00 | 04:00 | 14.1°C | 10.6°C | 0 | 2.2 | W | 38 | 1000 |
| 23:00 | 05:00 | 11.3°C | 7.8°C | 0 | 2.6 | W | 54 | 1001 |
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 — 40.000°, -105.250°, ERA5 grid cell center, 2.4 km from requested point
- Time zone
- America/Denver
- What's shown here
- The hourly and daily record for 13 May 2017 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 (40.00°N, 105.25°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.