Thunderstorms with lightning accompanied by gusty winds speed reaching 30-40 kmph is very likely to occur till Thursday.
Pathanamthitta, Ernakulam and Idukki districts have been placed under yellow alert for five days.
Adverse weather in the United Arab Emirates has caused some disruption to flights at Dubai's main airport.
The improvement is expected to be reflected in the air quality index as the day progresses -- the AQI at any given time is the average of readings taken in the last 24 hours.
It also said that heavy rains were likely at isolated places in the state between November 6 and 9.
The Met Department predicted isolated heavy rainfall in Kerala for the next few days due to the prevailing weather conditions over the southern part of the country.
A yellow alert was issued in Thiruvananthapuram, Kollam, Pathanamthitta, Alappuzha, Ernakulam, Thrissur, Palakkad, Malappuram and Kannur districts.
All districts except Kannur and Kasaragod have been placed under yellow alert on Monday.
As per the IMD forecast, Kerala will continue to witness moderate to heavy downpours with thunder and lightning till October 30.
Light to moderate rain is likely to intensify on October 29 and 30 in the state and IMD sounded yellow alert for several districts.