Home / Commack / 21 September 2017
Commack
United States · 21 September 2017
← 20 September 201722 September 2017 →
Average
22.4°C
low 21.6°C · high 23.6°C
Rainfall
0mm
dry day
Wind
5.6m/s
daily average
Humidity
73.1%
daily average
Cloud
100%
cover
Pressure
1015hPa
daily average
The temperature ranged from 21.6°C around 23:00 to 23.6°C around 16:00. No measurable rain was recorded during the day.
How unusual was this day?
Compared against the same 135 calendar days (±7 days) across the other 9 years on file.
High temperature
77th percentile
Low temperature
96th percentile
Rainfall
50th 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 19.9°C, versus 22.4°C on this specific day.
Sun & daylight
Sunrise
06:39
Sunset
18:51
Day length
12h 12m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/New_York.
Cumulative rainfall through the day.
| Local time | UTC | Temp | Feels | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 04:00 | 22.2°C | 21.3°C | 0 | 5.6 | NNW | 79 | 1013 |
| 01:00 | 05:00 | 22.1°C | 21°C | 0 | 5.7 | NNW | 79 | 1013 |
| 02:00 | 06:00 | 22°C | 20.7°C | 0 | 6 | NNW | 79 | 1013 |
| 03:00 | 07:00 | 21.8°C | 20.5°C | 0 | 6 | NNW | 80 | 1013 |
| 04:00 | 08:00 | 21.7°C | 20.4°C | 0 | 6 | NNW | 81 | 1013 |
| 05:00 | 09:00 | 21.7°C | 20.1°C | 0 | 6.3 | NNW | 80 | 1013 |
| 06:00 | 10:00 | 21.7°C | 19.5°C | 0 | 7 | N | 78 | 1014 |
| 07:00 | 11:00 | 21.8°C | 19.9°C | 0 | 6.5 | N | 78 | 1014 |
| 08:00 | 12:00 | 21.6°C | 19.9°C | 0 | 6.3 | N | 79 | 1015 |
| 09:00 | 13:00 | 21.8°C | 20.1°C | 0 | 6.4 | N | 80 | 1015 |
| 10:00 | 14:00 | 22.2°C | 20.7°C | 0 | 6.1 | N | 76 | 1016 |
| 11:00 | 15:00 | 22.8°C | 20.7°C | 0 | 6.4 | N | 70 | 1016 |
| 12:00 | 16:00 | 23°C | 21.3°C | 0 | 6 | N | 70 | 1016 |
| 13:00 | 17:00 | 23.1°C | 22.2°C | 0 | 4.8 | N | 69 | 1016 |
| 14:00 | 18:00 | 23.2°C | 22.6°C | 0 | 4.7 | N | 71 | 1015 |
| 15:00 | 19:00 | 23.4°C | 23°C | 0 | 4.6 | N | 71 | 1015 |
| 16:00 | 20:00 | 23.6°C | 22.7°C | 0 | 4.9 | N | 69 | 1015 |
| 17:00 | 21:00 | 23.5°C | 22.5°C | 0 | 4.9 | N | 68 | 1015 |
| 18:00 | 22:00 | 23.1°C | 22.3°C | 0 | 4.9 | NNE | 71 | 1015 |
| 19:00 | 23:00 | 22.9°C | 22.1°C | 0 | 4.6 | NNE | 70 | 1015 |
| 20:00 | 00:00 | 22.4°C | 21°C | 0 | 5 | NNE | 69 | 1016 |
| 21:00 | 01:00 | 22.2°C | 20.3°C | 0 | 5.3 | NNE | 65 | 1016 |
| 22:00 | 02:00 | 21.9°C | 19.4°C | 0 | 5.4 | NNE | 61 | 1016 |
| 23:00 | 03:00 | 21.6°C | 18.6°C | 0 | 5.9 | N | 62 | 1016 |
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
- Commack — 40.750°, -73.250°, ERA5 grid cell center, 10.9 km from requested point
- Time zone
- America/New_York
- What's shown here
- The hourly and daily record for 21 September 2017 specifically — not a monthly average. See the Commack 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 (2026-07-18). Historical climate data for Commack, United States (40.75°N, 73.25°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Commack, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 18, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Commack, 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 Commack, 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.