The short answer
On nearly every time-of-use plan in the US and Canada, electricity is cheapest overnight, roughly 11 pm to 6 am, and on weekends. It is most expensive on weekday evenings, usually a three-to-five-hour window inside 3 pm to 9 pm, and the gap is widest in summer.
Those two facts cover most households. The details that change from place to place are how long the peak window is, whether it applies on weekends, whether winter has a separate morning peak, and how big the price gap is. All of it is written on one page of your utility's tariff, and the sections below show what to look for.
One caveat before anything else: time only matters if your plan charges by time. On a flat or tiered rate, which is still how most US households are billed, a kilowatt-hour costs the same at 3 am as at 6 pm. If your bill shows a single energy charge, use the electricity cost calculator with your one rate and stop worrying about the clock. If it shows separate peak and off-peak kWh, read on. The bill-reading guide shows where on the bill to check.
Why the price changes through the day
The grid has to produce exactly as much power as everyone uses, second by second. Demand follows a daily shape that is remarkably similar across the continent:
- Overnight (11 pm to 6 am): the lowest demand of the day. Lights and appliances are off, businesses are closed, and the plants still running are the cheapest ones that run around the clock anyway: nuclear, hydro, large coal and combined-cycle gas, plus wind, which often blows hardest at night.
- Morning (6 to 10 am): a ramp as people wake up, shower, cook and commute. In cold weather this becomes a real peak, because electric heat is working hardest at dawn.
- Midday (10 am to 3 pm): moderate demand, and in sunny regions a flood of solar output. California regularly has more solar at midday than it can use, which is why some of its plans now price spring middays almost as low as overnight.
- Late afternoon and evening (3 to 9 pm): the expensive hours. Air conditioners have been fighting the day's heat, people come home and start cooking, lights go on, and solar output fades just as all of that happens. The grid covers the gap with its least efficient, most expensive plants, and pushes wires and transformers to their limits.
Time-of-use pricing passes that shape through to the bill. The peak price is not a penalty; it is closer to what those hours actually cost to supply, and the off-peak price is closer to what the cheap hours cost.
A typical day, hour by hour
Here is the shape of a common summer weekday schedule, priced relative to the US average residential rate of 18.34¢ per kWh (June 2026, EIA). The multipliers are representative of the plans described below, not one specific tariff.
| Hours (weekday, summer) | Period | Example price per kWh | Why |
|---|---|---|---|
| Midnight – 6 am | Super off-peak (some plans) | 8.3¢ | Lowest demand of the day; baseload and wind only |
| 6 am – 3 pm | Off-peak | 11.9¢ | Moderate demand, rising solar output |
| 3 pm – 4 pm | Mid-peak (shoulder) | 24.8¢ | AC load building, solar starting to fall |
| 4 pm – 9 pm | On-peak | 38.5¢ | Highest demand, least solar, most expensive plants running |
| 9 pm – midnight | Off-peak | 11.9¢ | Demand falling away |
| Weekends and holidays | Off-peak all day (outside California) | 11.9¢ | Offices and factories closed |
On this schedule the most expensive hour costs about 4.7 times as much as the cheapest one. Only five hours a day, on weekdays only, are actually on-peak: 25 of the week's 168 hours, or about 15%. Apart from that window and the one-hour shoulder, every hour is cheaper than the flat rate. That is why many households on time-of-use pay less without changing much; the plan rewards whatever you already do outside the peak.
Peak hours by region
Utilities publish their schedules in their tariff, and they do change, usually once every few years and announced well in advance. These are the typical patterns in 2026. Treat them as a guide to what to expect, and confirm the exact hours on your own utility's rate page.
| Region | Typical peak window | Cheapest hours | Notes |
|---|---|---|---|
| California (PG&E, SCE, SDG&E) | 4 pm – 9 pm, every day | Overnight; on some plans also spring middays | Weekends are not exempt. Most residential customers were moved to time-of-use by default. |
| Arizona | Weekday late afternoon, about 3 hours (APS: 4 pm – 7 pm) | Overnight and weekends | Short, sharp peaks driven by summer AC; plans often add a demand charge. |
| Colorado (Xcel) | 3 pm – 7 pm weekdays | 7 pm – 1 pm next day, weekends | A shoulder period from 1 pm to 3 pm on the default plan. |
| Michigan (DTE, Consumers) | DTE 3 pm – 7 pm; Consumers 2 pm – 7 pm (summer) weekdays | Evenings, overnight, weekends | Peak prices are highest June to September. |
| Texas (competitive market) | Depends on the retail plan; wholesale prices peak on summer evenings | "Free nights" plans: commonly 9 pm – 6 am | Retailers set the hours. Free-nights plans often charge more per kWh in the day to compensate. |
| Northeast and Mid-Atlantic | Usually weekday afternoons, often 2 pm – 7 pm in summer | Overnight and weekends | Mostly opt-in; flat or tiered rates remain the default for many. |
| Ontario, Canada (regulated TOU) | Summer 11 am – 5 pm; winter 7 – 11 am and 5 – 7 pm, weekdays | 7 pm – 7 am weekdays, all weekend | The optional Ultra-Low Overnight plan prices 11 pm – 7 am very low and puts a steep peak at 4 – 9 pm weekdays. |
The pattern is clear even with the local differences. Places with a lot of air conditioning and solar put the peak in the early evening. Places where summer AC drives demand through the hottest part of the day, like Ontario's summer schedule, put it across the afternoon. Places with electric heating add a winter morning peak. And overnight is cheap everywhere.
To find your own schedule, search your utility's name with "time of use rates" or "rate schedule", or look at the back of your bill, which usually names the rate code. The national map of average prices is in our electricity rates by state guide, where the cheapest state average is Nevada at 13.11¢ and the most expensive is Hawaii at 52.72¢. Time of use moves the price inside those averages by much more than the difference between most neighbouring states.
Seasons change the clock
Most time-of-use plans run two schedules a year:
- Summer (roughly June to September, sometimes May to October): one long evening peak and the widest price gap. This is when the expensive hours really bite, because central air is the biggest load most homes have.
- Winter (roughly October or November to May): either the same evening window with a smaller gap, or, in places with a lot of electric heating, a split peak on weekday mornings and early evenings with cheap hours across the middle of the day.
The practical effect is that the rule you learned in July may be wrong in January. If you set timers on a water heater or pool pump, check them when the season changes.
What the hours are worth, appliance by appliance
Using the example prices above, here is what one run of each large, movable load costs in each period. The kWh figures come from the same appliance data the calculator uses.
| Load (one run) | kWh | On-peak | Off-peak | Super off-peak |
|---|---|---|---|---|
| EV charger, Level 2 (7.2 kW), 1.5 h | 11 kWh | $4.16 | $1.29 | 89¢ |
| Electric water heater (40 gal tank), 3 h | 14 kWh | $5.20 | $1.61 | $1.11 |
| Pool pump, 1.5 HP, 8 h | 12 kWh | $4.62 | $1.43 | 99¢ |
| Clothes dryer, electric (per load), 1 h | 3.0 kWh | $1.16 | 36¢ | 25¢ |
| Dishwasher (one cycle), 1 h | 1.2 kWh | 46¢ | 14¢ | 10¢ |
| Electric oven, 1 h | 2.4 kWh | 92¢ | 29¢ | 20¢ |
Over a month the differences add up quickly for the big loads. Charging an electric car 1.5 hours a day at the on-peak price costs about $126 a month; the same charging after midnight costs about $27.10. An electric water heater doing its daily reheat in the evening costs $158 a month, against $48.92 if a timer keeps it off from 4 to 9 pm. Laundry, four dryer loads a week, is $20.03 a month at peak and $6.20 off-peak.
The oven is the honest exception. Dinner happens at peak by definition, and moving it saves about 64¢ a time. That is real but small, and nobody should eat at 10 pm to save it. A slow cooker started in the morning, which draws a fraction of the power, is the painless version.
What about air conditioning?
Air conditioning is the reason the peak exists, and the hardest load to move. A 3-ton central system running flat out during a five-hour peak can use more electricity in that window than everything else in the house combined. The workable strategy is pre-cooling:
- From about noon until the peak starts, set the thermostat a few degrees cooler than usual, around 72 to 74°F, while power is off-peak or mid-peak.
- When the peak starts, raise the setpoint to 78 to 80°F and let the house drift up slowly. The walls, floors and furniture you cooled act as a thermal battery.
- After the peak ends, return to your normal setting.
A well-insulated house can coast through most of a five-hour window this way, and a smart thermostat will run the schedule automatically; many utilities pay a sign-up credit for enrolling one. A leaky house warms up too quickly for it to work, and in that case a time-of-use plan may cost more than flat rate. Our air conditioner cost page shows what each hour of AC costs at your rate, and the time-of-use guide covers how to decide whether the plan is right for a household that runs the AC hard.
Using the cheap hours without thinking about them
The households that save on time-of-use are the ones that automate. Savings that depend on remembering to start the dishwasher at 10 pm stop after about a week.
- Electric car: set a charging schedule in the car or charger app to start after the off-peak window opens. The EV charging calculator shows what you save at your actual rates.
- Dishwasher and washer: use the delay-start button. Most machines offer 2 to 12 hours.
- Dryer: run it last thing at night, or first thing on a weekend morning.
- Electric water heater: a timer or a smart controller that blocks heating during the peak. A 40 to 50 gallon tank holds enough hot water to cover five hours.
- Pool pump: schedule the run hours overnight or in the morning, never in the late afternoon.
- Thermostat: a pre-cooling schedule in summer and, where there is a winter morning peak, a pre-heating schedule before it.
Then check the result. Most utility apps now show hourly usage from the smart meter; after a month you can see whether the big loads really moved. To estimate what any single appliance costs in each window, enter the wattage, hours and the peak or off-peak rate into the electricity cost calculator. For more ways to cut the bill that work on any plan, see how to lower your electricity bill.