Home / Tomball / 21 August 2018
Tomball
United States · 21 August 2018
← 20 August 201822 August 2018 →
Average
30.8°C
low 26°C · high 37.9°C
Rainfall
1.2mm
rain recorded
Wind
2.3m/s
daily average
Humidity
65.2%
daily average
Cloud
81%
cover
Pressure
1017hPa
daily average
The temperature ranged from 26°C around 06:00 to 37.9°C around 16:00. Rain was recorded across 2 hours, from around 18:00 to 19:00 (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
87th percentile
Rainfall
47th percentile
Wind
60th 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 28.8°C, versus 30.8°C on this specific day.
Sun & daylight
Sunrise
06:52
Sunset
19:56
Day length
13h 4m
Hour by hour
Temperature (line) and hourly rainfall (bars), local time — America/Chicago.
Cumulative rainfall through the day.
| Local time | UTC | Temp | Feels | Rain mm | Wind m/s | Dir | Humidity % | Pressure hPa |
|---|---|---|---|---|---|---|---|---|
| 00:00 | 05:00 | 28.8°C | 31.2°C | 0 | 3.7 | SSW | 69 | 1016 |
| 01:00 | 06:00 | 27.9°C | 30.5°C | 0 | 3.7 | SSW | 75 | 1017 |
| 02:00 | 07:00 | 27.7°C | 30.8°C | 0 | 3.6 | SSW | 78 | 1017 |
| 03:00 | 08:00 | 27.5°C | 30.8°C | 0 | 3.4 | SW | 81 | 1017 |
| 04:00 | 09:00 | 27.2°C | 30.9°C | 0 | 3.1 | SW | 83 | 1017 |
| 05:00 | 10:00 | 26°C | 29.2°C | 0 | 3.4 | SW | 87 | 1017 |
| 06:00 | 11:00 | 26°C | 29.3°C | 0 | 3.3 | WSW | 88 | 1017 |
| 07:00 | 12:00 | 26°C | 29.8°C | 0 | 2.9 | WSW | 88 | 1018 |
| 08:00 | 13:00 | 26.6°C | 30.7°C | 0 | 2.6 | WSW | 86 | 1018 |
| 09:00 | 14:00 | 28.2°C | 32.2°C | 0 | 2.8 | WSW | 79 | 1019 |
| 10:00 | 15:00 | 31.5°C | 33.9°C | 0 | 3 | W | 55 | 1019 |
| 11:00 | 16:00 | 33.1°C | 35.4°C | 0 | 2.9 | W | 50 | 1019 |
| 12:00 | 17:00 | 34.1°C | 36°C | 0 | 2.6 | W | 44 | 1019 |
| 13:00 | 18:00 | 35.3°C | 37.9°C | 0 | 2.1 | W | 42 | 1018 |
| 14:00 | 19:00 | 36.3°C | 39.5°C | 0 | 1.4 | W | 41 | 1018 |
| 15:00 | 20:00 | 37.1°C | 40.7°C | 0.03 | 0.8 | WSW | 39 | 1017 |
| 16:00 | 21:00 | 37.9°C | 41.1°C | 0.04 | 0.6 | SSW | 35 | 1016 |
| 17:00 | 22:00 | 37.6°C | 42.2°C | 0.03 | 0.5 | SW | 42 | 1015 |
| 18:00 | 23:00 | 35.1°C | 39.4°C | 0.63 | 1.2 | SSW | 49 | 1017 |
| 19:00 | 00:00 | 32.9°C | 37.9°C | 0.42 | 1.6 | S | 61 | 1017 |
| 20:00 | 01:00 | 30.9°C | 35.4°C | 0 | 1.5 | SE | 64 | 1017 |
| 21:00 | 02:00 | 29.6°C | 33.4°C | 0 | 1.9 | SSE | 67 | 1017 |
| 22:00 | 03:00 | 28.2°C | 33.1°C | 0 | 1.8 | SSE | 81 | 1018 |
| 23:00 | 04:00 | 28.5°C | 33°C | 0 | 2 | S | 78 | 1018 |
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
- Tomball — 30.000°, -95.500°, ERA5 grid cell center, 15.5 km from requested point
- Time zone
- America/Chicago
- What's shown here
- The hourly and daily record for 21 August 2018 specifically — not a monthly average. See the Tomball 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 Tomball, United States (30.00°N, 95.50°W), derived from ERA5 (Hersbach et al., 2023, Copernicus Climate Change Service). Retrieved from https://www.pastclimate.com/
PastClimate. (2026). Historical climate data for Tomball, United States [Data set]. Derived from ERA5 (Copernicus Climate Change Service). Retrieved July 21, 2026, from https://www.pastclimate.com/
"Historical Climate Data for Tomball, 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 Tomball, 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.