London Braces for Heat, Storms and a Cooler Midweek

It’s a classic start‑to‑summer tug‑of‑war here in London, Ontario – the sun is out, the humidity is hanging around like an unwelcome guest and, just when you think the heat might linger, a cooler spell is peeking over the horizon.

For Monday, July 20, the forecast is pretty straightforward: sunshine dominates the morning, then a few clouds drift in by the afternoon. Temperatures should climb to around 27 °C (that’s roughly 80 °F for those who prefer the Imperial), while the humidex, that handy little index that tells you how hot it feels, nudges up to 32. In other words, it’ll be warm, a touch sticky, but not unbearable.

Now, the real story begins after sunset. Environment Canada says the sky will start to clear, but there’s a 30 % chance that a few showers will sneak in before the night is over. It’s not a guarantee – it’s more of a “keep an eye on the sky” kind of warning.

Tuesday, July 21, looks to be the day the weather really throws a curveball. The day is expected to be the most unsettled of the bunch, with clouds building up in the morning and showers becoming increasingly likely as the sun climbs higher. By midday, the odds of rain could be anywhere between 30 % and 70 %. Add a decent risk of thunderstorms to that mix, and you might want to have an umbrella handy, just in case.

Temperatures on Tuesday will dip a little – the high should sit around 23 °C, but the humidex will still hover near 31, so the air will feel quite muggy. If you’re planning outdoor chores or a backyard barbecue, you might want to scout for a covered spot.

Wednesday, July 22, finally offers a breather. The forecast shifts back to a more comfortable mix of sun and clouds, with only a 30 % chance of lingering showers. Highs drop to about 21 °C, and the humidex eases, making it feel noticeably cooler than the previous two days.

All of these numbers are, of course, subject to change – weather forecasting is part science, part art, and Mother Nature is never shy about surprising us. Still, as of this morning’s 6:30 AM EDT update, Environment Canada’s outlook suggests a hot‑and‑humid start, a bout of rain and thunder on Tuesday, and a welcome cool‑down by mid‑week.

So, what’s the takeaway? Dress in layers you can peel off, keep a rain jacket handy, and enjoy the brief pause before the cooler days arrive. And if you’re curious about the details, the full forecast is available on the Environment Canada website – it’s always a good habit to check back for any updates.