Hot weather updates: Week of June 29, 2026

July 3, 2026 — 10:00 p.m.

ISO New England has lifted the precautionary Abnormal Conditions Alert. System conditions have returned to normal.

July 3, 2026 — 10:00 a.m.

ISO New England continues to monitor conditions on the regional electric grid as extremely hot, humid weather persists across the region.

Consumer demand for electricity peaked Thursday at 25,351 megawatts (MW), the highest level thus far in 2026, and in line with the ISO’s pre-summer forecasts.

ISO-NE is projecting slightly lower demand on Friday with a peak of 24,300 MW forecast. A typical summer day in New England peaks around 18,000 MW.

A region-wide precautionary alert remains in place, and ISO system operators have tools in place to handle unexpected events on the system.

Consumer demand is expected to remain elevated through Saturday before cooler weather enters the region beginning Sunday.

July 2, 2026 — 9:00 a.m.

ISO New England is expecting exceptionally tight operating conditions on the regional electric grid over the evening peak today, Thursday, July 2, 2026.

While current system forecasts show the region able to meet expected consumer demand and required operating reserves, there is little surplus generating capacity available to deal with unanticipated events. The extremely hot and humid weather is also affecting systems to the west and the north, including New York and Quebec, increasing uncertainty regarding energy imports to New England.

All available generating and demand-reducing resources are expected to be operating during the late afternoon and early evening hours.

Consumers across New England can help reduce stress on the power system by limiting their energy use from 4 to 8 p.m., when demand for electricity is typically the highest.  Actions like pre-cooling your home, using major appliances (such as washing machines, dryers, and dishwashers) during off-peak hours, or keeping curtains and blinds closed can help reduce overall system demand.

ISO New England will continue to monitor system conditions throughout the day and provide updates here, as needed. You can also monitor system conditions on the ISO to Go app.

July 1, 2026 — 5:00 p.m.

ISO New England has issued a precautionary alert for all of New England due to hot, humid weather across the region and anticipated tight operating conditions over the evening peak on July 2, 2026. This is not a system emergency.

June 30, 2026 — 11:00 a.m.

ISO New England is closely monitoring system conditions as hot, humid weather is expected to drive high electricity demand across the region over the coming days.

At this time, ISO-NE expects the regional power system will have sufficient resources to meet anticipated demand. While this predicted demand would be the highest so far this year, the projections are in line with the ISO’s forecasts for the summer.

Forecasters are indicating temperatures will reach the upper 90s to low 100s later this week in parts of southern New England, including Boston and Hartford, the region’s two largest centers of electricity demand. Hot weather is expected to continue through the holiday weekend.

During periods of high electricity demand, consumers can help reduce the amount of power needed by being mindful of their energy use during the peak-use hours of 4 to 8 p.m.

As of Tuesday morning, the ISO is forecasting the following peak electric loads:

Wednesday, July 1: 23,950 MW

Thursday, July 2: 25,850MW

Friday, July 3: 24,000 MW

Saturday, July 4: 21,950 MW

Peak demand is the time when electricity use is expected to be highest. For additional context, 1 MW of electricity can serve about 750 to 1,000 average homes in New England.

ISO New England’s system operators monitor grid conditions around the clock and are well-trained to handle increased seasonal demand, unexpected generation loss, or transmission outages. The ISO has a range of tools and procedures available to mitigate concerns if system conditions change. For more detailed information, visit the Seven-Day Capacity Forecast page.