Home / Roy / 21 September 2017
Roy
United States · 21 September 2017
← 20 September 201722 September 2017 →
Average
9.2°C
low 4.6°C · high 12.3°C
Rainfall
6mm
rain recorded
Wind
2m/s
daily average
Humidity
78%
daily average
Cloud
87%
cover
Pressure
1006hPa
daily average
The temperature ranged from 4.6°C around 23:00 to 12.3°C around 00:00. Rain was recorded across 12 hours, from around 01:00 to 23:00 (6mm total).
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
1th percentile
Low temperature
5th percentile
Rainfall
92th percentile
Wind
68th 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 16.7°C, versus 9.2°C on this specific day.
Sun & daylight
Sunrise
07:14
Sunset
19:26
Day length
12h 11m
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 | 12.3°C | 9.3°C | 0 | 2.2 | N | 56 | 1002 |
| 01:00 | 07:00 | 11.1°C | 8.7°C | 0.25 | 1.8 | NNW | 64 | 1003 |
| 02:00 | 08:00 | 11.4°C | 9.2°C | 0.13 | 1.6 | NW | 64 | 1004 |
| 03:00 | 09:00 | 10.9°C | 8.8°C | 0.17 | 1.3 | NW | 65 | 1004 |
| 04:00 | 10:00 | 9.1°C | 7.4°C | 0.06 | 1 | NW | 78 | 1005 |
| 05:00 | 11:00 | 8.8°C | 6.8°C | 0.04 | 1.7 | NW | 83 | 1005 |
| 06:00 | 12:00 | 8.6°C | 6.5°C | 0 | 1.7 | NW | 85 | 1005 |
| 07:00 | 13:00 | 8.4°C | 6.4°C | 0.01 | 1.7 | NW | 88 | 1006 |
| 08:00 | 14:00 | 9.2°C | 7.1°C | 0.01 | 1.9 | NW | 83 | 1006 |
| 09:00 | 15:00 | 10.3°C | 7.9°C | 0.01 | 2.1 | NW | 73 | 1007 |
| 10:00 | 16:00 | 10.6°C | 8.5°C | 0.03 | 1.7 | NW | 72 | 1007 |
| 11:00 | 17:00 | 10.9°C | 8.7°C | 0.04 | 1.7 | WNW | 68 | 1007 |
| 12:00 | 18:00 | 10.9°C | 8.4°C | 0.06 | 2 | NW | 69 | 1007 |
| 13:00 | 19:00 | 11.3°C | 8.6°C | 0.26 | 2.4 | NW | 68 | 1006 |
| 14:00 | 20:00 | 10.5°C | 7.5°C | 0.14 | 2.8 | NW | 72 | 1006 |
| 15:00 | 21:00 | 10.4°C | 7.2°C | 0.06 | 3.3 | NNW | 74 | 1005 |
| 16:00 | 22:00 | 8.8°C | 5.3°C | 0.05 | 3.6 | NW | 80 | 1004 |
| 17:00 | 23:00 | 8.4°C | 4.7°C | 0.1 | 3.7 | NW | 82 | 1006 |
| 18:00 | 00:00 | 7.8°C | 4.4°C | 0.33 | 3.3 | NW | 84 | 1007 |
| 19:00 | 01:00 | 7.7°C | 4.7°C | 0.44 | 2.6 | NW | 85 | 1009 |
| 20:00 | 02:00 | 7°C | 4.7°C | 0.74 | 1.8 | NW | 89 | 1010 |
| 21:00 | 03:00 | 5.9°C | 3.8°C | 1 | 1.5 | NW | 94 | 1011 |
| 22:00 | 04:00 | 5.2°C | 3.5°C | 1.41 | 0.8 | WNW | 97 | 1012 |
| 23:00 | 05:00 | 4.6°C | 3.1°C | 0.63 | 0.4 | E | 98 | 1011 |
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
- Roy — 41.250°, -112.000°, ERA5 grid cell center, 10.1 km from requested point
- Time zone
- America/Denver
- What's shown here
- The hourly and daily record for 21 September 2017 specifically — not a monthly average. See the Roy 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 (2026-07-19). Historical climate data for Roy, United States (41.25°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 Roy, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 19, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Roy, United States." PastClimate, derived from ERA5 (Copernicus Climate Change Service), July 19, 2026, www.pastclimate.com.
@misc{pastclimate,
author = {PastClimate},
title = {Historical climate data for Roy, United States},
year = {2026},
note = {Derived from ERA5 (Hersbach et al., 2023), Copernicus Climate Change Service. Accessed 2026-07-19},
url = {https://www.pastclimate.com/}
}Notice something wrong with this data? Report a data issue.