Katy climate — normals and trends
Katy (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 20.5 °C and it receives 1,068 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (28.3 °C on average) and the coldest is January (11.2 °C). Rainfall peaks in May.
Katy averages 9 frost days, 129 hot days (≥ 30 °C) and 123 rainy days per year.
Katy has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The hottest day of the period reached 42.7 °C (on 27 August 2023) and the coldest -17.2 °C (on 31 January 1949).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
KatyTexas
- coords
- 29.79°, -95.82°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
20.5°C
Average daily high
25.9°C
Average daily low
15.8°C
Annual rainfall
1,068mm
Sunshine / day
9.4h
Mean relative humidity
74%
Average peak wind
18.1km/h
Seasonal range
17.1°C
Frost days (< 0 °C)
9 d/yr
Hot days (≥ 30 °C)
129 d/yr
Rainy days (≥ 1 mm)
123 d/yr
Annual snowfall
0.8 cm
Average feels-like high
27.0 °C
Average feels-like low
16.1 °C
Average peak gust
35.5 km/h
Tropical nights (≥ 20 °C)
149 d/yr
Solar radiation
16.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.44 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
42.7 °C
27 August 2023
Coldest day
-17.2 °C
31 January 1949
Wettest day
238 mm
11 September 1961
Windiest day
75.0 km/h
11 September 1961
Strongest gust
148.7 km/h
12 September 1961
Hottest feels-like
46.2 °C
21 June 2023
Coldest feels-like
-21.5 °C
31 January 1949
Snowiest day
10.8 cm
30 January 1949
Sunniest day
13.3 h
2 June 1948
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 14.2 °C | -2.4 °C | 110 mm | +21 mm |
| Feb | 19.9 °C | +1.3 °C | 73 mm | -3 mm |
| Mar | 25.8 °C | +3.7 °C | 60 mm | -21 mm |
| Apr | 28.3 °C | +2.5 °C | 69 mm | -27 mm |
| May | 31.1 °C | +1.8 °C | 140 mm | +32 mm |
| Jun | 32.3 °C | +0.1 °C | 196 mm | +100 mm |
| Jul | 33.8 °C | +0.4 °C | 94 mm | +15 mm |
| Aug | 33.9 °C | +0.2 °C | 135 mm | +54 mm |
| Sep | 32.6 °C | +1.4 °C | 53 mm | -43 mm |
| Oct | 31.0 °C | +3.6 °C | 59 mm | -25 mm |
| Nov | 26.0 °C | +4.2 °C | 74 mm | -16 mm |
| Dec | 20.7 °C | +2.5 °C | 35 mm | -55 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Katy?
Katy has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 20.5 °C and it receives 1,068 mm of precipitation per year.
What is the hottest day ever recorded in Katy?
The hottest day measured in Katy between 1940 and 2025 was 27 August 2023, reaching 42.7 °C.
What is the coldest day in Katy?
The coldest day measured in Katy between 1940 and 2025 was 31 January 1949, at -17.2 °C.
Does it snow in Katy?
Almost never: Katy sees virtually no snow, with about 9 frost days per year.
Has the climate of Katy warmed?
Yes: Katy warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Katy?
The wettest day measured in Katy between 1940 and 2025 was 11 September 1961, with 238 mm of rain in 24 hours.
What was the windiest day in Katy?
The windiest day measured in Katy between 1940 and 2025 was 11 September 1961, with winds reaching 75.0 km/h.
What is the warmest month in Katy?
The warmest month in Katy is July (28.3 °C on average); the coldest is January (11.2 °C).
How much does it rain in Katy?
Katy receives on average 1,068 mm of precipitation per year, spread over about 123 rainy days.
Is it sunny in Katy?
Katy gets on average 9.4 hours of sunshine per day, roughly 3,431 hours per year over 1940-2025.
What is the biggest single-day snowfall in Katy?
The heaviest 24-hour snowfall measured in Katy between 1940 and 2025 was 30 January 1949, with 10.8 cm.
Are there tropical nights in Katy?
Yes: Katy has on average 149 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Katy?
In Katy, between 1940 and 2025, the highest apparent temperature reached 46.2 °C on 21 June 2023, and the lowest was -21.5 °C on 31 January 1949.
Compare Katy with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Katy