The southwest monsoon has set in over Kerala, the India Meteorological Department (IMD) said on Thursday. This marks the start of India's four-month rainy season that is crucial for agriculture, water supplies and inflation management.Travellers planning trips across southern and western India may need to keep a close eye on the weather forecast. The weather agency has issued multiple rain and thunderstorm warnings as the southwest monsoon continues to advance, bringing intense showers, strong winds and possible travel disruptions in several states.ALSO READ: India weather updateFrom Kerala and Tamil Nadu to Karnataka, Goa and Maharashtra, weather conditions are expected to remain active over the coming days, affecting road, rail and air travel in some regions.For travellers, this means possible delays, waterlogging in urban areas, reduced visibility on highways and disruptions to outdoor tourism activities.ALSO READ: Annapurna Bhandar goes live in West BengalKerala Under Multiple Rain AlertsKerala, where the monsoon has already made its presence felt, remains on high alert. The IMD issued an orange alert in Alappuzha, Kottayam and Ernakulam districts on Thursday morning, warning of thunderstorms accompanied by heavy rain and surface wind speeds of up to 40 kmph.ALSO READ: ThynkTech Pune India closureThe weather agency has also forecast thunderstorms with moderate rainfall and winds reaching 40 kmph in Thiruvananthapuram, Kollam, Pathanamthitta, Idukki and Thrissur districts.Tourists visiting Kerala's backwaters, hill stations and coastal destinations are advised to stay updated on local weather advisories before heading out.Tamil Nadu Faces Heavy to Very Heavy RainfallKerala's neighbouring state Tamil Nadu is also expected to witness intense monsoon activity. The IMD has warned of very heavy rainfall in Kanyakumari district and heavy rain in several other regions of the state as the southwest monsoon strengthens over southern India.According to the weather department, Kanyakumari could receive very heavy rainfall over the next five days. Heavy showers are also likely in Tenkasi and Tirunelveli districts, along with the hilly and adjoining regions of:NilgirisCoimbatoreTheniTiruppurDindigulErodeSalemDharmapuriKrishnagiriTirupatturVelloreRanipetTiruvannamalaiThe IMD has also predicted moderate rain accompanied by thunderstorms and lightning in Chennai and surrounding suburban areas during the next 24 hours.Popular Tourist Destinations May See DisruptionsSeveral destinations that attract large numbers of tourists during this season could experience weather-related interruptions. Travellers heading to destinations such as Munnar, Alleppey, Wayanad, Kanyakumari, Ooty and the Nilgiris region should be prepared for sudden downpours, slippery roads and reduced visibility.Adventure activities, trekking routes and boat services may also be temporarily suspended depending on local weather conditions.Impact on Flights, Trains and Road TravelHeavy rainfall often affects transportation networks during the monsoon season. Passengers are advised to:Check flight status before leaving for airports.Monitor railway updates for possible delays.Avoid unnecessary travel during thunderstorm warnings.Keep extra travel time for journeys through rain-affected regions.Follow advisories issued by local authorities and disaster management agencies.Those travelling through hilly regions should remain cautious about landslides and road closures during periods of intense rainfall.What Travellers Should PackIf you're travelling to monsoon-affected regions over the next few days, consider carrying:Waterproof jackets or ponchosQuick-dry clothingWaterproof footwearPower banksWaterproof bags for electronics and documentsEssential medicinesKeeping digital and physical copies of travel documents can also be helpful in case of weather-related disruptions.Outlook for the Coming DaysThe IMD expects monsoon conditions to remain active across parts of southern India in the coming days. With heavy rain, thunderstorms and gusty winds likely in several states, travellers are advised to stay informed and plan journeys accordingly.While the rains offer welcome relief from summer heat and transform landscapes into lush green destinations, they can also bring sudden disruptions. Checking the latest weather updates before travel remains the best way to ensure a safe and comfortable trip.