Sunshine and heat, both in heavy doses, will be the theme Sunday and for the next few days, according to the National Weather Service’s daily and extended forecasts.

An upper-level ridge of high atmospheric pressure, which typically squeezes out any hopes of clouds forming, will continue building over Texas on Sunday, leading to rain-free and mostly clear skies, and higher temperatures.

“High temperatures… Sunday are forecast in the the low to mid-90s across the Hill Country and along and east of I-35 and I-37, in the upper 90s along the U.S. 90 corridor west of San Antonio, and 100 to 104 degrees along the Rio Grande,” the weather service said in its forecast bulletin Saturday.

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In San Antonio, we can expect partly sunny skies that gradually becoming sunnier. Temperatures that start at 71 degrees or so just before dawn will soar to around 94 in the afternoon, forecasters said.

Light south-southeast winds carrying moisture-laden air from the Gulf of Mexico means plenty of humidity with the heat. The air temperatures will be in the low 90s but the heat index values, which measure temperatures based on humidity’s effect on the body, will approach the triple digits.

100 degrees in San Antonio this week?

We can expect more of the same for the coming work week, as the high atmospheric pressure holds fast in Texas and low-level air flow from the Gulf of Mexico continues through Wednesday, forecasters said.

The biggest news, though, will be the rising temperatures, which could reach 100 degrees in San Antonio by the end of this week. Record highs will be possible along the Rio Grande, and the weather service said it might be prompted to issue heat health alerts starting Tuesday.

San Antonio’s forecast for Monday calls for sunshine and southerly winds of 5 to 10 mph. Afternoon temperatures will peak at 94 degrees, but humidity ought to make those temps feel like they’re almost 100.

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We could see a few more clouds on an otherwise sunny Tuesday as the ridge of high atmospheric pressure starts to shift to the east. Humidity brought in by the south-southeast winds will make the daily high temperature of 97 feel more like 105 degrees.

Wednesday will be similar to Tuesday: Expect mostly sunny skies and persistent south-southeast winds with gusts as strong as 20 mph. Temperatures rising to an afternoon high of 96 again will feel more 105 degrees because of the elevated humidity.