Gromiljak climate — normals and trends
Gromiljak (Bosnia and Herzegovina) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 9.2 °C and it receives 946 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 (18.8 °C on average) and the coldest is January (-1.2 °C). Rainfall peaks in November.
Gromiljak averages 97 frost days, 9 hot days (≥ 30 °C) and 143 rainy days per year.
Gromiljak has warmed by +2.9 °C between 1940 and 2025, or +0.34 °C per decade. This trend is statistically significant.
The number of frost days there went from about 118 to 76 per year over the period.
The hottest day of the period reached 37.6 °C (on 10 August 2017) and the coldest -29.1 °C (on 8 January 2017).
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
GromiljakFederation of Bosnia and Herzegovina
- coords
- 43.97°, 18.06°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.2°C
Average daily high
14.0°C
Average daily low
4.8°C
Annual rainfall
946mm
Sunshine / day
8.2h
Mean relative humidity
76%
Average peak wind
9.7km/h
Seasonal range
20.0°C
Frost days (< 0 °C)
97 d/yr
Hot days (≥ 30 °C)
9 d/yr
Rainy days (≥ 1 mm)
143 d/yr
Annual snowfall
166.0 cm
Average feels-like high
12.4 °C
Average feels-like low
2.8 °C
Average peak gust
30.3 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
13.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.9 °C
since 1940
+0.3 °C per decade · r² = 0.62 · 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
37.6 °C
10 August 2017
Coldest day
-29.1 °C
8 January 2017
Wettest day
79 mm
19 December 1968
Windiest day
32.7 km/h
10 April 1973
Strongest gust
107.6 km/h
13 December 1957
Hottest feels-like
38.6 °C
16 August 2024
Coldest feels-like
-33.7 °C
8 January 2017
Snowiest day
37.2 cm
14 November 2004
Sunniest day
14.7 h
24 June 2025
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 | 7.1 °C | +4.7 °C | 47 mm | -28 mm |
| Feb | 7.1 °C | +2.4 °C | 55 mm | -23 mm |
| Mar | 13.0 °C | +4.1 °C | 188 mm | +105 mm |
| Apr | 16.2 °C | +2.5 °C | 70 mm | -17 mm |
| May | 18.7 °C | +0.4 °C | 66 mm | -21 mm |
| Jun | 27.8 °C | +6.0 °C | 2 mm | -81 mm |
| Jul | 27.7 °C | +3.6 °C | 58 mm | -10 mm |
| Aug | 26.5 °C | +1.9 °C | 32 mm | -24 mm |
| Sep | 23.7 °C | +3.1 °C | 51 mm | -14 mm |
| Oct | 14.0 °C | -1.3 °C | 92 mm | +18 mm |
| Nov | 10.5 °C | +1.5 °C | 141 mm | +43 mm |
| Dec | 6.5 °C | +2.5 °C | 26 mm | -66 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 Gromiljak?
Gromiljak has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 9.2 °C and it receives 946 mm of precipitation per year.
What is the hottest day ever recorded in Gromiljak?
The hottest day measured in Gromiljak between 1940 and 2025 was 10 August 2017, reaching 37.6 °C.
What is the coldest day in Gromiljak?
The coldest day measured in Gromiljak between 1940 and 2025 was 8 January 2017, at -29.1 °C.
Does it snow in Gromiljak?
Yes. Gromiljak gets on average 166.0 cm of snow per year and has around 97 frost days.
Has the climate of Gromiljak warmed?
Yes: Gromiljak warmed by +2.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Gromiljak?
The wettest day measured in Gromiljak between 1940 and 2025 was 19 December 1968, with 79 mm of rain in 24 hours.
What was the windiest day in Gromiljak?
The windiest day measured in Gromiljak between 1940 and 2025 was 10 April 1973, with winds reaching 32.7 km/h.
What is the warmest month in Gromiljak?
The warmest month in Gromiljak is July (18.8 °C on average); the coldest is January (-1.2 °C).
How much does it rain in Gromiljak?
Gromiljak receives on average 946 mm of precipitation per year, spread over about 143 rainy days.
Is it sunny in Gromiljak?
Gromiljak gets on average 8.2 hours of sunshine per day, roughly 2,993 hours per year over 1940-2025.
What is the biggest single-day snowfall in Gromiljak?
The heaviest 24-hour snowfall measured in Gromiljak between 1940 and 2025 was 14 November 2004, with 37.2 cm.
Are there tropical nights in Gromiljak?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Gromiljak.
What was the most extreme apparent temperature in Gromiljak?
In Gromiljak, between 1940 and 2025, the highest apparent temperature reached 38.6 °C on 16 August 2024, and the lowest was -33.7 °C on 8 January 2017.
Compare Gromiljak with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Gromiljak