Canadian wildfire smoke rolled into Boston by Tuesday afternoon, blocking much of the sun and turning the sky a hazy yellowish-brown. It also took the edge off the heat: Boston reached 90 degrees, well below the 97 degrees that had been forecast.
That is why people looking up today are seeing an orange, murky sun instead of a bright blue sky. The smoke absorbed the peak heating of the day and arrived earlier than expected, changing the feel of a hot stretch that had been headed toward mid-90s heat.
The smoke was not just a Boston problem. It blanketed much of Southern New England, and scattered air quality alerts were expected across the region. When smoke hangs low enough to filter sunlight, it can do two things at once: dull visibility and shave a few degrees off the high temperature. That is what happened Tuesday, when the haze kept Boston about 5 to 10 degrees cooler than the forecast.
There is a sharp contrast between what the heat might have done and what the smoke actually allowed. Boston was headed for 97 degrees, but the high stopped at 90. The difference matters because the smoke is not only changing the color of the sky; it is changing the day people are living through, outdoors and indoors alike.
The setup for Wednesday looks similar, even if the details shift. More hazy skies were expected in the morning, with heavier smoke lingering over portions of Southern New England, including Boston. Another hot day was expected, but wildfire smoke may again keep temperatures a nudge cooler, with a front sliding south through the region and sparking scattered showers. The rain was expected to be pretty light, though Boston could get caught in a brief passing shower.
Behind the haze is a complex atmosphere that can move smoke quickly once it reaches the jet stream, sending the plume downstream over New England. The smoke was described as coming from an explosion of wildfires in Canada and Minnesota, but the effect on the ground was plain by Tuesday afternoon: a dimmed sun, a yellow-brown sky and a cooler-than-expected high. For now, the answer to why is the sun orange today is simple enough — smoke is still in the air, and it is still filtering the light.
