Het weer in Kuala Lumpur (KL) in mei

Regulars name this month as sitting inside the specific window, roughly May through September, when seasonal agricultural burning in Sumatra can drift haze over the city on the prevailing southwest winds - a real, checkable risk tied to wind direction rather than a constant feature. Our row backs the intense heat and rain, 32.3C reading as a severe 38C at 85 percent humidity, over 23.6C nights, with a striking 231.5mm of rain across 25 days. Regulars are candid the haze's actual severity varies significantly year to year depending on the burning and the wind, so it's a real possibility to check closer to travel dates rather than a guaranteed feature of the month. Rain itself is described as typically brief, arriving early morning or late afternoon rather than continuously. The record: 9.1 hours of sun, a 9.3 kph wind and AQI 115.

December sits in the north-east monsoon, and the first thing regulars say is that it belongs to the other side of the peninsula: the mountain range shields this city and the west coast, and the flooding people read about is an east-coast story. What falls here is heavy and short - a thunderstorm in the late afternoon or evening for a couple of hours, with sun earlier in the day. Our 270.6mm across 25.5 days is that pattern at its wettest, under 32C reading as 38C at 88 percent humidity. The compensation is the air: AQI 87, the cleanest month of this city's year, because the rain that soaks December also washes it. The record: 8 hours of sun.

Regulars call June as good a month as any here, because the south-west monsoon from May to September is the least wet part of a wet year - and our numbers agree, 195.1mm against November's 399.5mm. What the season does not reduce is the number of rainy days: 22.8 of them, which is the board's own description of the pattern. Sunny mornings, then heavy but short showers in the late afternoon and early evening. So outdoor plans go before lunch and the afternoon has an indoor answer. The other half of the same season is haze, blown over from Sumatran burning, and our AQI column carries it - 121 this month against 87 in December. Rain clears it. 32.8C reading as 39C at 85 percent humidity. The record: 24C nights and 9.5 hours of sun.

Kuala Lumpur-forum threads on August flag the haze risk honestly: it can only happen during the south-west monsoon window of May to September, when winds carry smoke over from Sumatran slash-and-burn fires, and it isn't guaranteed every year - several posters who visited in August report no real problem beyond ordinary big-city haze. The shower pattern gets the same even-handed treatment: typical tropical afternoon or early-evening downpours lasting about an hour, not full days lost to it. The record shows just how much falls over a month even so: 32.4C days feeling like a sticky 38C, 23.9C nights, 203mm spread across 24.4 days, and an AQI of 112 - August's own record runs properly soaked and hazy even setting the cross-border smoke aside.