The heatwave in Northern California will impact the Foothills differently than the Sacramento Valley.

In a case like this, inversion sets in, which means temperatures get warmer as you go up in elevation.

For this weekend, many Valley locations will see overnight lows in the 60s with the help of a light Delta Breeze. The Foothills will see early morning temperatures in the 75-80 degree range. Places like Grass Valley, Foresthill, Placerville and Plymouth will see very warm mornings.

In the afternoons, the trend will reverse and the Foothills will be a little cooler than the Valley.

California’s expected heat wave is set to begin today, with triple-digit high temperatures forecast to be 106 degrees by 4 p.m. Thursday.

While Thursday morning was comfortable, many Valley spots will reach the 106-degree range by mid-afternoon. Friday and Saturday will be a little less hot, with the highest temperatures ranging from 102-104 degrees.

But the worst heat is likely to come on Sunday and Monday. Morning temperatures on those days will be in the upper 60s, and the afternoons will rise to the 108-110-degree range. There is even the possibility of some heat records being set on those days.

"The impact days are Sunday, Monday and Tuesday, and I think that Labor Day will be one for the record books at 110 degrees," meteorologist Tamara Berg said.

However, there is some respite on the horizon. Some cooling is expected in the middle of next week.

Scroll through for the forecast below:

KCRA 3’s weather team is calling Sunday through Tuesday heat impact days with highs forecast in the 108-111 range in the Valley. That means people should plan around the heat in the afternoons, especially students with after-school activities.

This is the kind of heat you will want to plan around for the Labor Day holiday weekend. Make use of the cooler morning hours for any strenuous activities and try to limit your outdoor exposure between 3 p.m. to 6 p.m.

The forecast is likely to change a little over the next few days, but you can make plans now to try to stay cool this week.

The hot weather will dry fuels meaning fires can start quickly and spread faster.

If you are going to be camping this weekend, be very careful with any campfires and do not leave them unattended.

Be aware of your surroundings and be ready to move if you see or smell smoke.

Fire officials across the region are worried that the high heat, paired with the dry conditions, will spread fires easier. Sacramento Metro Fire Captain Parker Wilbourn said that it is especially concerning with many people expected to grill outside, including in the wildland areas, during the holiday weekend.

"With the conditions being so hot, we are on edge," Wilbourn said. "Sometimes it just takes that small spark, whether it be from a barbecue or a chain hitting the ground from a trailer or any open flame at a campsite, a small spark can create a very large wildfire that threatens our communities and threatens our homes.”

KCRA 3’s weather team has developed a tool the team will be using to keep you informed as fire conditions change. It’s called the Fire Threat Index. This will give you an idea of the fire risk on any given day in different areas of our coverage region so you can plan ahead.

Toggle below to see the Fire Threat Index for different parts of Northern California over the next few days:

The Fire Index will stay in the High category until cooler weather arrives next week.

| Weather Resources | Important numbers for outages, more

Cooling centers across Northern California are set to open starting Thursday to allow some residents to get a break from the forecasted week of triple-digit heat.

| Read More | Here are the cooling centers opening Thursday amid forecast triple digits in NorCal

California's grid operator is asking people to conserve power for three days in a row as it extended its Flex Alert.

Cal ISO announced on Thursday it would extend its Flex Alert into Friday hours after Gov. Gavin Newsom signed an executive order meant to ramp up the state's energy supply temporarily.

Residents are urged to conserve electricity from 4 p.m. until 9 p.m.

| MORE | Flex Alert issued for Californians amid forecasted triple-digit temperatures

Customers can help ease pressure on the grid by easing power usage between 4 p.m. and 9 p.m:

| Video Below | California residents asked to ease power usage as temperatures rise in coming week

The Sacramento County Division of Public Health and Office of Emergency Services in a release Wednesday recommends that outdoor events between noon to 8 p.m. from Saturday to Tuesday be canceled.

This includes youth sports, community gatherings, parades, marches or any events that could involve children, the elderly or any people with compromised immune systems that may be sensitive to the heat.

The Sacramento region will be under a Spare the Air day on Thursday due to air quality being at unhealthy levels for sensitive groups.

KCRA 3 Meteorologist Heather Waldman explains what that means in the video below.

Here's where to find our latest video forecast. You can also watch a livestream of our latest newscast here. The banner on our website turns red when we're live.

We're also streaming on the Very Local app for Roku, Apple TV or Amazon Fire TV.

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