You’ll be able to feel the summer weather creeping up through the rest of the week and even through the weekend as temperatures notch up, humidity rises and the heat index begins to show up in forecasts.

Even though the weather service has a 20 percent chance of rain in the forecast for Friday, that chance keeps shrinking and may disappear. That diminishing chance of rain is from another front that should fall apart before it arrives, a pattern we’ve seen repeated this month.

This could be the weekend to give in and switch on the air conditioner. Saturday and Sunday temperatures should be pushing into the high 80s, and in the afternoons the heat index temperatures could reach 93 or 94. The dew points will inch into the 70s, about the point where we start to grumble and feel a tad uncomfortable.

Then on Sunday night another front will arrive, this one moving south of the state. It should provide a 30 percent to 50 percent chance of thunderstorms on Monday that will taper off into the evening.

That front will drop the humidity early next week to a slightly more comfortable level.

Some fog over areas away from the coast should continue to build until about 9 a.m. today. Most of it won’t be too thick, cutting visibility to a mile or so.

But there are some spots out there such as eastern Hernando County where the soupy air is dropping visibility down to about the length of your headlight beam. Some of the patchy areas out there can mean visibility of one-quarter mile or less.

Also, some fog is forming along Interstate 4 through Polk County, especially in the areas that usually get it.

Later today you could see a repeat of the air pollution warning that came out Tuesday. The same weather conditions - that on Tuesday afternoon allowed ozone to nudge into levels unhealthy for people sensitive to the pollutant - could hang around today.

The high-pressure area that’s keeping the sky rain-free also is preventing air from the ground to mix with air at higher levels, trapping pollution down here where we breathe. Lots of times you’ll hear this called an inversion.

When air doesn’t mix, pollution near the ground builds during the day and reaches levels that spark air quality alerts in the afternoon. The same thing happened last week. The ozone pollution level tends to be fine during the morning and starts to build as the sun heats pollution, mostly from car exhaust, and converts it to ozone.

On Tuesday, pollution started building to the unhealthy levels in southwest Hillsborough County during the early afternoon. That’s where ozone pollution frequently seems to start. Eventually the pollution spread over nearly all the Tampa Bay area and much of Central Florida.

The temperature on Tuesday peaked at 88 at Tampa International Airport, and the forecast for today is 89.

The good news is that the pollution level only nosed into the unhealthy range on Tuesday and last week. Health officials consider ozone pollution unhealthy when the air quality index is from 101 to 150. The reading on Tuesday and last week was 101, just inside the unhealthy range.

As long as the humidity stays low, we’re in for a run of great weather. So far forecasts toward the end of the week still keep that humidity fairly low, though it is nudging upward.

And just as that humidity starts to get to the point where we begin whining, a weak cold front will arrive over the weekend and bring in some drier air. At least that’s what forecasters are saying now. The front will fall apart, they think, over Northern Florida and isn’t going to do anything to our temperatures, just buy us a bit more time before the muggy summer arrives.

We’ll be coming close to summer-type temperatures and humidity near the weekend, with temperatures in the high 80s and dew points touching 70. You can tell by the morning lows in the 70s, a sign of increasing humidity.

We might as well enjoy this while it lasts.

Morning fog, though not everywhere, is thick enough in places to cut visibility to one-quarter mile or less. The weather service says it could linger into midmorning as low clouds stay around.

Visibility is fine in Tampa, but places to the east and north have patchy areas where it’s pretty thick. Visibility in Lakeland and eastern Hillsborough is down to one-quarter mile, and it’s the same in eastern Hernando County and around the Villages in Sumter County.

Even though a stalled front broke apart over West Central Florida and towed in some dry air, there’s enough moisture around to combine with the relatively low temperatures and create fog.

Once it lifts, we’re facing another day of sun, few clouds, only the barest chance of rain and temperatures in the middle 80s.

The weather service expects temperatures to climb though the week and eventually reach the upper 80s or lower end of the 90s, especially toward the weekend, though the long-range forecast still calls for the morning lows to remain below 70.

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