San Miguel de Tucuman lies in a transition zone between temperate climates to the south, and subtropical climates to the north. Summers are hot and long, falls arrive relatively late, winters are extremely dry and pleasant, and springs tend to be hot and dry, becoming more humid later. The precipitation pattern is monsoonal: out of the 848 mm (33.4 in) that fall annually, 667 mm (26.2 in) fall in the hottest 5 months, the other 7 being essentially dry.
In the summer, one can expect daytime highs ranging from 30°C (86F) to 35°C (95F) with very high humidity; at night, 18°C (64F) to 23°C (73F) are the norm. Heat waves are frequent, and bring temperatures up to 40°C (104F); however, some relief is possible after cold fronts, which are less usual than further south, or during intense precipitation.
April marks the beginning of the fall, but temperatures remain warm: 21°C to 27°C (70F to 81F) during the day, and 12°C to 18°C (54F to 64F) at night, with less rainfall. Winter is short and relatively mild; days usually average 15°C (59F) to 21°C (70F) and nights go from 4°C (39F) to 10°C (50F). Winter warm spells with days up to 30°C (86F) are common, as well as cold waves that keep afternoon temperatures around 10°C (50F). Frost can occur in the winter but is usually light, almost always above -2°C (28F). Snow is extremely rare, but in 2007, it reached the city centre. There have been other episodes of sleet and snow in the mountains around the city, and in 2010, sleet was reported downtown again, a very rare event.
Springs are very short, and by October, summer weather settles in the city, with highs beyond 30°C (86F) very common. This is due to the dryness of the season: daytime highs are close to those in the summer, when rainfall and clouds are persistent, whereas spring is often sunny and arid
