Select units of measurement for the temperature and rainfall tables (metric or imperial).
Average weather, temperature, rainfall, sunshine hours
In Bologna, the capital of the Emilia-Romagna region, located in the Po Valley, there is a
semi-continental climate. Winters are quite cold and damp, while summers are hot and muggy.
The city is located in the south-eastern part of the Po Valley, 70 km (45 mi) away from the Adriatic Sea.
Precipitation is moderate, since it amounts to 670 millimeters (26.4 inches) per year; the rains are fairly well distributed over the seasons, even though there are two peaks in spring and autumn and two relative minima in winter and summer. Summer is the season in which the rains are less frequent; in summer and in late spring, they may occur in the form of thunderstorm.
Winter, from December to February, is cold, humid and dull. Temperatures can remain around 0 °C (32 °F) even during the day, especially in December and January, and the sky remains overcast for many days.
Fog, which in the past was fairly frequent, has become rarer in recent decades, to the point that now, it only occurs in periods when the Atlantic high pressure system dominates.
The wind is generally weak or absent, although the southwest mild wind that descends from the Apennines and comes from central Italy can sometimes blow, while at other times, the north-east cold wind blows.
There is a moderate amount of rainy days, although the winter is the driest season.
Snow in Bologna generally falls at least once every year, and sometimes can be abundant; during the heaviest snowfalls, snow depth usually reaches 25-30 centimeters (10/12 inches), though it reached 75 cm (30 in) in January 1985, and 95 cm (37 in) in February 2012. Snow in Bologna occurs during cold spells, when the Bora, the cold wind from Eastern Europe, which is initially dry, acquires moisture on the Adriatic Sea and then it's forced to rise when it meets the Apennines. Fortunately, in the old town, you can comfortably walk under the arcades, protected from rain or snow.
During the most intense
cold spells, nighttime lows can drop below -10 °C (14 °F).
The temperature reached -14 °C (7 °F) in February 1956, -13.5 °C (7.5 °F) in January 1960, -16.5 °C (2.5 °F) in January 1963, -13.5 °C (7.5 °F) in December 1963, -14.5 °C (6 °F) in January 1968, -19 °C (-2 °F) in January 1966 (record), -17 °C (1.5 °F) in January 1979, -16.5 °C (2.5 °F) in January 1985, -15 °C (5 °F) in February 1991, -13 °C (8.5 °F) in December 2009, and -12 °C (10.5 °F) in February 2012.
Typically, by the second half of February, the temperature tends to rise, and highs can quite easily exceed 10/12 °C (50/54 °F).
Spring in Bologna is initially unstable, and gradually becomes a pleasant season, especially from mid-April to late May, when there are many sunny days, with mild or pleasantly warm temperatures during the day. In March, however, the first mild days alternate with the return of cold weather; it can be cold also in April, especially in the first half of the month. Atlantic depressions able to bring rainfall are quite frequent. By May, the first heat thunderstorms may occur.
Summer, from June to August, is hot and muggy, and generally sunny.
The air feels hotter because of humidity and poor ventilation, conditions typical of the Po Valley; it is true that we are close to Romagna, which receives a bit of breeze from the sea, but it is also true that within the city, the heat is trapped between buildings.
During
hot periods, the temperature quite easily reaches 34/35 °C (93/95 °F), and sometimes up to 37/38 °C (99/100 °F). In July 1983 and August 2017, it reached 40 °C (104 °F), and in August 2003, 39.5 °C (103 °F). In the summer of 2003, the temperature reached or exceeded 35 °C (95 °F) for nine days in June, nine days in July, and nineteen days in August.
On summer evenings, strictly after sunset, in the city center, locals spend time outdoors to get some air. However, the city is close to the hills, and in the southern suburbs, you can find, in the evening and at night, a temperature a few degrees lower and a bit of breeze from the mountains.
Sometimes, even in summer, Atlantic disturbances, able to bring a bit of rain and cool weather, can affect this area, especially in June and late August, or thunderstorms can break out in the afternoon or in the evening, but the sun shines and the temperature is high for long periods.
Autumn offers fine days in September, and sometimes in early October, then quickly becomes gray and rainy enough. The first cold days usually occur in November. On the whole, autumn is the rainiest season of the year.
The amount of
sunshine in Bologna is low from mid-October to February, when the sun is rarely seen, and even when it comes out, it is often weak and veiled in mist (though it goes a bit better than in Milan and in the western Po Valley). On the other hand, sunshine is quite frequent in spring, and it is very frequent in summer, except in the rare rainy days or when sunny days are interrupted by afternoon thunderstorms. On average there are about 2,000 hours of sunshine per year.
Best Time
The
best times to visit Bologna are spring and early summer, especially from mid-April to mid-June. September, too, is a good month. However, you have to take into account some rainy days in both periods.
Summer, on the contrary, can be hot, although it may bring also some acceptable days, especially in June. You have to take into account, in the summer and sometimes in May, some thunderstorms in the afternoon or in the evening.
In summer, you can reach the sea, on the Adriatic Riviera, if there is not too much traffic, in an hour's drive or a little more.
Bologna - Climate data
In Bologna, the
average temperature of the coldest month (January) is of
3.5 °C, that of the warmest month (July) is of
25.4 °C. Here are the average temperatures.
Bologna - Average temperatures (1991-2020) |
| Month | Min | Max | Mean |
|---|
| January | -0.2 | 7.2 | 3.5 |
|---|
| February | 0.7 | 9.9 | 5.3 |
|---|
| March | 4.3 | 15.2 | 9.7 |
|---|
| April | 8.1 | 19.1 | 13.6 |
|---|
| May | 12.7 | 24 | 18.4 |
|---|
| June | 17 | 28.6 | 22.8 |
|---|
| July | 19.3 | 31.5 | 25.4 |
|---|
| August | 19.2 | 31.4 | 25.3 |
|---|
| September | 14.9 | 25.8 | 20.4 |
|---|
| October | 10.8 | 19.3 | 15.1 |
|---|
| November | 5.7 | 12.8 | 9.2 |
|---|
| December | 0.8 | 7.7 | 4.3 |
|---|
| Year | 9.5 | 19.4 | 14.45 |
|---|
amounts to
670 millimeters per year: so, it is at an intermediate level. It ranges from
35 millimeters in the driest month (January) to
75 millimeters in the wettest one (April). Here is the average precipitation.
Bologna - Average precipitation| Month | Days |
|---|
| January | 35 | 6 |
|---|
| February | 45 | 6 |
|---|
| March | 55 | 7 |
|---|
| April | 75 | 8 |
|---|
| May | 60 | 8 |
|---|
| June | 55 | 6 |
|---|
| July | 40 | 4 |
|---|
| August | 50 | 5 |
|---|
| September | 65 | 5 |
|---|
| October | 70 | 7 |
|---|
| November | 70 | 6 |
|---|
| December | 50 | 6 |
|---|
| Year | 670 | 75 |
|---|
There are on average around 2040
sunshine hours per year. Here are the average hours of sunshine per day.
Bologna - Sunshine hours| Month | Average | Total |
|---|
| January | 2.5 | 80 |
|---|
| February | 3.5 | 95 |
|---|
| March | 5 | 150 |
|---|
| April | 6 | 175 |
|---|
| May | 7.5 | 230 |
|---|
| June | 8.5 | 255 |
|---|
| July | 9.5 | 290 |
|---|
| August | 8.5 | 260 |
|---|
| September | 6.5 | 200 |
|---|
| October | 5 | 150 |
|---|
| November | 2.5 | 80 |
|---|
| December | 2.5 | 75 |
|---|
| Year | 5.6 | 2040 |
|---|
Bologna - Weather by month
Based on the period 1991-2020
January, the coldest month of the year, is generally a cold month. The average temperature is of
3.5 °C, with a minimum of
-0.2 °C and a maximum of
7.2 °C.
On the coldest nights of the month, the temperature usually drops to around
-5 °C. However, it dropped to
-8.6 °C in January 2006.
On the warmest days of the month, the temperature usually reaches around
14 °C. However, it reached
20.7 °C in January 2000.
Precipitation amounts to
35 mm, distributed over 6 days.
The day lasts on average 9 hours and 20 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 27% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
7.7 kph.
February is generally a quite cold month. The average temperature is of
5.3 °C, with a minimum of
0.7 °C and a maximum of
9.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-4.5 °C. However, it dropped to
-15 °C in February 1991.
On the warmest days of the month, the temperature usually reaches around
17 °C. However, it reached
24.9 °C in February 1998.
Precipitation amounts to
45 mm, distributed over 6 days.
The day lasts on average 10 hours and 30 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 32% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is of
8.5 kph.
March is generally a mild month. The average temperature is of
9.7 °C, with a minimum of
4.3 °C and a maximum of
15.2 °C.
On the coldest nights of the month, the temperature usually drops to around
-1.5 °C. However, it dropped to
-9.7 °C in March 2005.
On the warmest days of the month, the temperature usually reaches around
22.5 °C. However, it reached
27 °C in March 2012.
Precipitation amounts to
55 mm, distributed over 7 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 41% of the time.
The average humidity is 67%.
The average wind speed is of
9.6 kph.
April is generally a mild month. The average temperature is of
13.6 °C, with a minimum of
8.1 °C and a maximum of
19.1 °C.
On the coldest nights of the month, the temperature usually drops to around
2.5 °C. However, it dropped to
-2.7 °C in April 2003.
On the warmest days of the month, the temperature usually reaches around
26 °C. However, it reached
30.6 °C in April 2011.
Precipitation amounts to
75 mm, distributed over 8 days.
The day lasts on average 13 hours and 30 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 67%.
The average wind speed is of
10.1 kph.
May is generally a warm month. The average temperature is of
18.4 °C, with a minimum of
12.7 °C and a maximum of
24 °C.
On the coldest nights of the month, the temperature usually drops to around
7.5 °C. However, it dropped to
2 °C in May 1991.
On the warmest days of the month, the temperature usually reaches around
30.5 °C. However, it reached
34.9 °C in May 2009.
Precipitation amounts to
60 mm, distributed over 8 days.
The day lasts on average 14 hours and 50 minutes. So the days are long.
There are on average 7.5 hours of sunshine per day. So, the sun shines 50% of the time.
The average humidity is 64%.
The average wind speed is of
10.2 kph.
June is generally a warm to hot month. The average temperature is of
22.8 °C, with a minimum of
17 °C and a maximum of
28.6 °C.
On the coldest nights of the month, the temperature usually drops to around
12 °C. However, it dropped to
8.2 °C in June 1996.
On the warmest days of the month, the temperature usually reaches around
35 °C. However, it reached
38.3 °C in June 2019.
Precipitation amounts to
55 mm, distributed over 6 days.
The day lasts on average 15 hours and 30 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 8.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 61%.
The average wind speed is of
10.1 kph.
July, the hottest month of the year, is generally a warm to hot month. The average temperature is of
25.4 °C, with a minimum of
19.3 °C and a maximum of
31.5 °C.
On the coldest nights of the month, the temperature usually drops to around
15 °C. However, it dropped to
12.2 °C in July 2004.
On the warmest days of the month, the temperature usually reaches around
36.5 °C. However, it reached
39.6 °C in July 1999.
Precipitation amounts to
40 mm, distributed over 4 days.
The day lasts on average 15 hours and 5 minutes. So the days are long.
There are on average 9.5 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 58%.
The average wind speed is of
10.1 kph.
August is generally a warm to hot month. The average temperature is of
25.3 °C, with a minimum of
19.2 °C and a maximum of
31.4 °C.
On the coldest nights of the month, the temperature usually drops to around
14 °C. However, it dropped to
9.7 °C in August 1995.
On the warmest days of the month, the temperature usually reaches around
36.5 °C. However, it reached
40.1 °C in August 2017.
Precipitation amounts to
50 mm, distributed over 5 days.
The day lasts on average 13 hours and 55 minutes.
There are on average 8.5 hours of sunshine per day. So, the sun shines 60% of the time.
The average humidity is 60%.
The average wind speed is of
9.6 kph.
September is generally a warm month. The average temperature is of
20.4 °C, with a minimum of
14.9 °C and a maximum of
25.8 °C.
On the coldest nights of the month, the temperature usually drops to around
9.5 °C. However, it dropped to
6.7 °C in September 2002.
On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
34.8 °C in September 2015.
Precipitation amounts to
65 mm, distributed over 5 days.
The day lasts on average 12 hours and 30 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 66%.
The average wind speed is of
9.1 kph.
October is generally a very mild month. The average temperature is of
15.1 °C, with a minimum of
10.8 °C and a maximum of
19.3 °C.
On the coldest nights of the month, the temperature usually drops to around
4.5 °C. However, it dropped to
0 °C in October 1997.
On the warmest days of the month, the temperature usually reaches around
26 °C. However, it reached
29.8 °C in October 1997.
Precipitation amounts to
70 mm, distributed over 7 days.
The day lasts on average 10 hours and 55 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is of
7.8 kph.
November is generally a mild month. The average temperature is of
9.2 °C, with a minimum of
5.7 °C and a maximum of
12.8 °C.
On the coldest nights of the month, the temperature usually drops to around
-0.5 °C. However, it dropped to
-7.2 °C in November 1993.
On the warmest days of the month, the temperature usually reaches around
20 °C. However, it reached
23.2 °C in November 2002.
Precipitation amounts to
70 mm, distributed over 6 days.
The day lasts on average 9 hours and 35 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 28% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is of
7.6 kph.
December is generally a quite cold month. The average temperature is of
4.3 °C, with a minimum of
0.8 °C and a maximum of
7.7 °C.
On the coldest nights of the month, the temperature usually drops to around
-5 °C. However, it dropped to
-13.2 °C in December 2009.
On the warmest days of the month, the temperature usually reaches around
14 °C. However, it reached
19 °C in December 1992.
Precipitation amounts to
50 mm, distributed over 6 days.
The day lasts on average 8 hours and 55 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 2.5 hours of sunshine per day. So, the sun shines 27% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is of
7.8 kph.