The climate of Rajasthan can be divided into four seasons:
Pre-Monsoons, Monsoon, Post-Monsoon and Winter.
Pre-monsoon, which extends from April to June, is the
hottest season, with temperatures ranging from 32oC
to 45oC. In western Rajasthan the temp may rise
to 48C, particularly in May and June. At this time,
Rajasthan only hill station, Mt Abu registers the lowest
temperatures. In the desert regions, the temperatures drops
in night. Prevailing winds are from the west and sometimes
carry dust storms (we call them andhi).
The second season Monsoon extends from July to September,
temp drops but humidity increases making it very un
comfortable, even when there is slight drop in the temp (35oC
to 40oC). We have about 90% of our rains in this
period.
The Post-monsoon period is from Oct to December. The average
maximum temperature is 33oC to 38oC,
and the minimum is between 18oC and 20oC.
The fourth season is the winter or cold season, from January
to March. There is a marked variation in maximum and minimum
temperatures, and regional variations across the state.
January is the coolest month of the year. And temp may drop
to 0oC in some cities of Rajasthan, like Churu.
There is slight precipitation in the north and north-eastern
region of the state, and light winds, predominantly from the
north and north-east. At this time, relative humidity ranges
from 50% to 60% in the morning, and 25% to 35% in the
afternoon.