Heavy to very heavy rainfall with extremely heavy falls are likely over Assam, Meghalaya, Sub-Himalayan West Bengal and Sikkim during the next five days.
The Regional Meteorological Centre (RMC) at Guwahati has issued an orange alert, while for other districts, a yellow alert has been issued.
The Met department said that the very heavy rainfall may cause flash floods in several cities of the state.
The weather department advised people to avoid working in the fields during the spell of thunderstorm and lightning period.
Fairly widespread to widespread light or moderate rainfall with isolated heavy to very heavy rainfall is very likely over Northeast states during 5 days.
In addition, isolated heavy rainfall is also on the cards over Gangetic West Bengal on July 3; over Jharkhand from July 3-4, and over Odisha from July 3-7.
Thunderstorms with lightning over Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, West Bengal, Sikkim, Odisha, Jharkhand, Bihar, Uttarakhand, Tamil Nadu, Puducherry and Karaikal.