Radar & lightning: Latest D.C. area radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

If there was any doubt summer is lurking, that doubt probably shrank a bit today as highs reached the mid-80s to near 90. While we’ve seen hotter, humidity levels are way up, and that goes a long way toward making the overall discomfort factor. Another day to broil is on tap tomorrow before we slowly trend cloudier and wetter as we head through the week.

Through Tonight: After an isolated to scattered shower and storm risk (40% chance) moves through this evening, we should be mostly calm overnight, though a very isolated shower is possible late night. Otherwise, partly cloudy and warm — lows are mostly in the near 60 to mid-60s range, but downtown may stay closer to 70.

Tomorrow (Tuesday): It’s partly cloudy, muggy and hot by afternoon. Highs head up to around 90 degrees. And with dew points well into the mid-and-upper 60s, we see heat indices heading for the mid-90s. While I can’t rule out a shower or storm (which could be strong), it doesn’t appear anything widespread happens during the day since the main energy is still west with the slowly approaching storm system. So, probably isolated to scattered again at most.

See Jason Samenow’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

The Washington Monument is seen from Virginia. (Brian Allen via Flickr)

Pollen update: Tree pollen remains high at 584 grains/cubic meter of air. Grass pollen and mold spores are also on the rise, now both reaching moderate to high levels locally. Weed pollen is low but starting to show up now as well.