Weather and climate in Bologna (Emilia Romagna)

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.
The monthly average temperature ranges from 3.5 °C (38.3 °F) in January to 25.5 °C (78 °F) in July. Here are the average temperatures.

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. Here is the average precipitation.

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. Here are the average sunshine hours per day.

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 - Weather by month

Based on the period 1991-2020

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January, the coldest month of the year, is generally a cold month. The average temperature is of 3.5 °C (38 °F), with a minimum of -0.2 °C (31.7 °F) and a maximum of 7.2 °C (44.9 °F).
On the coldest nights of the month, the temperature usually drops to around -5 °C (23 °F). However, it dropped to -8.6 °C (16.5 °F) in January 2006.
On the warmest days of the month, the temperature usually reaches around 14 °C (57 °F). However, it reached 20.7 °C (69.3 °F) in January 2000.
Precipitation amounts to 35 mm (1.4 in), 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 8 kph (5 mph).

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February is generally a quite cold month. The average temperature is of 5.3 °C (42 °F), with a minimum of 0.7 °C (33.3 °F) and a maximum of 9.9 °C (49.9 °F).
On the coldest nights of the month, the temperature usually drops to around -4.5 °C (23.5 °F). However, it dropped to -15 °C (5 °F) in February 1991.
On the warmest days of the month, the temperature usually reaches around 17 °C (62.5 °F). However, it reached 24.9 °C (76.8 °F) in February 1998.
Precipitation amounts to 45 mm (1.8 in), 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 9 kph (5 mph).

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March is generally a mild month. The average temperature is of 9.7 °C (49 °F), with a minimum of 4.3 °C (39.7 °F) and a maximum of 15.2 °C (59.3 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -1.5 °C (29.5 °F). However, it dropped to -9.7 °C (14.5 °F) in March 2005.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 22.5 °C (73 °F). However, it reached 27 °C (80.6 °F) in March 2012.
Precipitation amounts to 55 mm (2.2 in), 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 10 kph (6 mph).

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April is generally a mild month. The average temperature is of 13.6 °C (56 °F), with a minimum of 8.1 °C (46.6 °F) and a maximum of 19.1 °C (66.3 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 2.5 °C (36.5 °F). However, it dropped to -2.7 °C (27.1 °F) in April 2003.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 26 °C (78.5 °F). However, it reached 30.6 °C (87.1 °F) in April 2011.
Precipitation amounts to 75 mm (3 in), 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 10 kph (6 mph).

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May is generally a warm month. The average temperature is of 18.4 °C (65 °F), with a minimum of 12.7 °C (54.9 °F) and a maximum of 24 °C (75.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 7.5 °C (46 °F). However, it dropped to 2 °C (35.6 °F) in May 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 30.5 °C (86.5 °F). However, it reached 34.9 °C (94.8 °F) in May 2009.
Precipitation amounts to 60 mm (2.4 in), 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 10 kph (6 mph).

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June is generally a warm to hot month. The average temperature is of 22.8 °C (73 °F), with a minimum of 17 °C (62.7 °F) and a maximum of 28.6 °C (83.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 12 °C (53.5 °F). However, it dropped to 8.2 °C (46.8 °F) in June 1996.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 35 °C (94.5 °F). However, it reached 38.3 °C (100.9 °F) in June 2019.
Precipitation amounts to 55 mm (2.2 in), 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 10 kph (6 mph).

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July, the hottest month of the year, is generally a warm to hot month. The average temperature is of 25.4 °C (78 °F), with a minimum of 19.3 °C (66.8 °F) and a maximum of 31.5 °C (88.7 °F).
On the coldest nights of the month, the temperature usually drops to around 15 °C (58.5 °F). However, it dropped to 12.2 °C (54 °F) in July 2004.
On the warmest days of the month, the temperature usually reaches around 36.5 °C (97.5 °F). However, it reached 39.6 °C (103.3 °F) in July 1999.
Precipitation amounts to 40 mm (1.6 in), 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 10 kph (6 mph).

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August is generally a warm to hot month. The average temperature is of 25.3 °C (78 °F), with a minimum of 19.2 °C (66.6 °F) and a maximum of 31.4 °C (88.5 °F).
On the coldest nights of the month, the temperature usually drops to around 14 °C (57.5 °F). However, it dropped to 9.7 °C (49.5 °F) in August 1995.
On the warmest days of the month, the temperature usually reaches around 36.5 °C (97.5 °F). However, it reached 40.1 °C (104.2 °F) in August 2017.
Precipitation amounts to 50 mm (2 in), 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 10 kph (6 mph).

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September is generally a warm month. The average temperature is of 20.4 °C (69 °F), with a minimum of 14.9 °C (58.8 °F) and a maximum of 25.8 °C (78.5 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 9.5 °C (49.5 °F). However, it dropped to 6.7 °C (44.1 °F) in September 2002.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 31.5 °C (88.5 °F). However, it reached 34.8 °C (94.6 °F) in September 2015.
Precipitation amounts to 65 mm (2.6 in), 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 9 kph (6 mph).

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October is generally a very mild month. The average temperature is of 15.1 °C (59 °F), with a minimum of 10.8 °C (51.4 °F) and a maximum of 19.3 °C (66.8 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 4.5 °C (40.5 °F). However, it dropped to 0 °C (32 °F) in October 1997.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 26 °C (79 °F). However, it reached 29.8 °C (85.6 °F) in October 1997.
Precipitation amounts to 70 mm (2.8 in), 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 8 kph (5 mph).

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November is generally a mild month. The average temperature is of 9.2 °C (49 °F), with a minimum of 5.7 °C (42.3 °F) and a maximum of 12.8 °C (55 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -0.5 °C (31 °F). However, it dropped to -7.2 °C (19 °F) in November 1993.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 20 °C (68 °F). However, it reached 23.2 °C (73.8 °F) in November 2002.
Precipitation amounts to 70 mm (2.8 in), 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 8 kph (5 mph).

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December is generally a quite cold month. The average temperature is of 4.3 °C (40 °F), with a minimum of 0.8 °C (33.5 °F) and a maximum of 7.7 °C (45.8 °F).
On the coldest nights of the month, the temperature usually drops to around -5 °C (23 °F). However, it dropped to -13.2 °C (8.2 °F) in December 2009.
On the warmest days of the month, the temperature usually reaches around 14 °C (57.5 °F). However, it reached 19 °C (66.2 °F) in December 1992.
Precipitation amounts to 50 mm (2 in), 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 8 kph (5 mph).