Lying at the foothills of the Alleghenies, Pittsburgh experiences a lot of overcast weather: Precipitation falls about 150 days a year, with the most rainy days in March and April. In winter, it's cloudy with occasional snow (20-44 in/50-112 cm), and January temperatures range 19-34 F/-5 to -2 C, occasionally dropping to 0 F/-18 C or below. Temperatures are comfortable during April and May (39-70 F/3-21 C).
It can be humid in the summer. Expect July temperatures to range 61-82 F/16-32 C, with occasional readings above 90 F/32 C. July has the most frequent thunderstorms. August and September are usually clear and warm; October is fair and crisp (42-62 F/5-16 C). In general, spring and fall are the best times to visit.