With average highs of 85 and average lows of 70, yesterday, today and tomorrow are the climatologically warmest days of the year. The average low on the 23rd dips to 69 degrees and that marks the beginning of the long, slow slide back to winter. The National Climate Data Center map above shows the dates of warmest weather around the country and they range from early June in the desert Southwest, before the monsoon arrives, to late September along the West Coast.
We won't be anywhere near the warmest day of the year today or tomorrow, although the humidity will be on the increase. Today's high will be 83 or so and Tuesday will be a couple degrees warmer. The heat and humidity are expected to peak on Wednesday when the high will be in the sticky upper 80s. That's not all that impressive, but it is enough that we have to watch out for heavy rain in the form of showers or thunderstorms from Wednesday afternoon until a cold front passes through the region sometime Thursday.
The forecasts are, surprisingly, not in agreement as we head into the weekend. Generally, with high pressure in charge we should see dry weather, more sun than clouds and highs in the lower 80s Friday and Saturday with perhaps more humidity and clouds on Sunday.