Parma, where it is

In Parma, there is a humid temperate climate. Winters are quite cold and damp, while summers are hot and muggy. The monthly average temperature ranges from 3 °C (37 °F) in January to 25 °C (77 °F) in July.
The city is located in the western part of the Emilia-Romagna region, where the climate has the characteristics of the Po valley more than in the eastern part.
Winter, from December to February, is cold, humid and dull. Temperatures can remain around freezing even during the day, especially in December and January, and the sky remains overcast for long periods. Fog, once frequent, has become rarer in recent decades, and lately, it only occurs in periods dominated by an Atlantic high pressure system.
Snow generally falls at least once every year, and sometimes can be abundant. Generally, during the most abundant snowfalls, the snow depth reaches 25/30 centimeters (0.8/1 foot), but in February 1929, it reached 80 cm (2.6 feet). Snow can fall both during cold spells, with the wind blowing from the north-east (as happens in Bologna), and with the wind blowing from the south at high altitude (as happens in Milan).
During the most intense cold spells, which in the last few decades have become rarer, nighttime lows can drop to around -15/-20 °C (-4/5 °F). In January 1985, the temperature dropped to -18 °C (0.5 °F) at the university and to -25 °C (-13 °F) in the hinterland. In February 2012, it reached -18 °C (0.5 °F) at the airport.

Piazza Garibaldi under the snow

Summer, from June to August, is hot and muggy, and generally sunny. In hot weather, the temperature can reach 35/37 °C (95/99 °F). Weak wind and high humidity make the heat unpleasant, even though, just before midnight, a slight breeze starts to blow from the Apennines, which are not far away. The wind from the Ligurian Sea, the "Marino", manages to reach the city more easily in spring and autumn, while in winter and summer, the wind is generally weak or absent.
Here are the average temperatures (for the period 2005-2018).
Parma - Average temperatures
Min (°C)014913171918151160
Max (°C)681419242831302519126
Min (°F)323439485563666459524332
Max (°F)434657667582888677665443

Precipitation in Parma is moderate, given that it amounts to 770 millimeters (35.5 inches) per year. The rains are fairly well distributed throughout the year, although there are two maxima in spring and autumn, and two relative minima in winter and summer. Summer is the season when the rains are rarer; in this season and in late spring, they can occur in the form of thunderstorm (but much less than in Milan). Here is the average precipitation.
Parma - Average precipitation

The amount of sunshine in Parma is not good from mid-October to February, when the sun rarely shines, and even when it comes out, it is often weak and veiled in a mist. The sun, on the other hand, is not lacking in the spring, and is very frequent in summer, except for the rare rainy days or when sunny days are interrupted by afternoon thunderstorms. Here are the average sunshine hours per day.
Parma - Sunshine

When to go

The best times to visit Parma are spring and early summer, particularly from mid-April to mid-June. September is also a good month. However, some rainy days must be taken into account in both periods.
Summer can be very hot, although it can give some acceptable days, especially in June. You have to take into account, in summer and sometimes in May, some afternoon or evening thunderstorms.