Heading into next week and beyond, the worst of the heat is expected more in states in the south-central and western contiguous US.
When and where will the heat wane? Where does extreme heat remain?
Large sections of the eastern half of the US still face a Level 4 out of four extreme heat risk, including significant swaths of the Ohio Valley and the Mid-Atlantic.
High temperatures in these areas are expected to reach the mid-30s to around 37C in most locations today, which is about 10 to 15 degrees above average.
But by tomorrow, the heat dome of high pressure that has been centred near the Mid-Atlantic will become less distinct, and its core will return closer to its typical home in the Southeast US.
Much of the Midwest and parts of the Mid-Atlantic will remain under major to extreme heat risk.
Then on Saturday, the most intense heat will be centred on the Ohio Valley before more typical - but still hot - summertime conditions take over.
What the forecast looks like for several cities
There will be major relief for some spots that have recently been cooking. For others, not so much. Here’s what six cities can expect in the days ahead.
- Boston: Around 30 today down from a June record of 38.8, reached yesterday. Turning much cooler , with highs only around 21. On Saturday, maybe even lower with a few showers. In the 20s again later this weekend.
- New York: Ranging across the 30s, from the upper 30s in adjacent New Jersey to the low 30s northeast of the city. Shower and storm chances as daytime temperatures dip into the low 20s, then remain there on Saturday. Back into the high 20s for Sunday.
- Washington: Upper , 30s with mid-30s tomorrow and an increased chance of showers or storms. Heat index about 10 degrees hotter. In the high 20s on Saturday before near or above 30 returns for the weekend.
- Raleigh, North Carolina: Near-record highs of 37 or above and in the upper 30s tomorrow. Mid- and upper 30s are likely for the weekend.
- Columbus, Ohio: Mid-30s, with the heat index near 40.5. Temperatures somewhat down in the next two days but still at least in the low 30s. Readings may rise again ahead of the cold front this weekend.
- Nashville: highs around 37 and a heat index near 43.3. Mid-to upper 30s should persist through the weekend.
Numerous June records
As warned by forecasts, 37-degree temperature readings were widespread yesterday.
In addition to the June top mark in Boston of 38.8, the high there was only just off its record of 40.
The temperature in Newark reached 39.4. In downtown Baltimore, a somewhat questionable reading of 40.5 was observed. The temperature at John F. Kennedy International Airport in New York hit 38.8. All of these are top marks for June.
Every state in New England hit record highs for the month, as did New York state and Maryland.
Locations unusually far north recorded extreme values. It was 38.8 in North Hartland, in central Vermont, a record for June in that state. Maine and New Hampshire also reached the century mark, with 37 in several locations for the former and 38 for the latter.
At least 600 records for high temperatures and 1200 for warm lows were set over the past week ending yesterday, according to NOAA data.
What’s next for the heat?
It appears the highest temperatures will migrate west heading through next week and perhaps beyond. An overall summery pattern - given that it is almost July, it’s not unexpected - looks likely for the Lower 48 in the foreseeable future.
The centre of the heat dome may end up pushing toward the south-central US and, ultimately, towards the Four Corners of the Southwest. This could mean somewhat less intense weather on the East Coast, bouts of extreme heat across the Western US to the southern Plains and an increase in monsoonal moisture into the arid Southwest.
