Adelaide is well known for its dry summer heat, but there's a humidity and heaviness in the air today which has locals feeling decidedly uncomfortable.

"It doesn't feel like Adelaide," local resident Tory Shepherd told Weatherzone at 10 am local time, when the temperature had already topped 32°C with humidity hovering around a moderate 30%, but potentially on the rise.

"We're proud of our dry heat here and if we travel interstate to somewhere like Sydney or Brisbane in summer, we're always saying 'oh, it's muggy, isn't it?'

"I was speaking to a couple of people who were out walking and because we're all Covid anxious and we were sweating more than usual, and we sort of thought, uh-oh, what could this be?'

"Luckily it was just the humidity. It has been noticeably humid here for a few days and now we've got the heat to go with it."

Image: Henley Beach jetty is far from the worst place to escape the heat and humidity. Source: @jalarangeira via Pixabay.

So how hot and humid is it?

Adelaide is heading for a top of 39°C today and 37°C on Wednesday.

Usually, when Adelaide temps approach 40°C, the humidity dips down below about 20% in dry northerly winds, but today's set-up is a bit different.

While upper-level northerlies have dragged hot air down over the city, the prevailing ground-level winds are from the east and are tapping into the moisture over NSW.

You can see a representation of easterly winds carrying moisture from NSW/VIC towards Adelaide on this graphic showing surface dew point and wind for Tuesday afternoon.

This 'moist' air is increasing the relative humidity in Adelaide and other area in southern SA today. Earlier this morning, it topped 50% at Mt Lofty.

So will it rain, or is it just going to stay muggy and uncomfortable?

For those hoping for a good garden soaking, this is all a bit of a tease unfortunately.

Adelaide has thus far received only a very light sprinkle of rain so far in 2022 – and there's not much rain in sight on the horizon, give or take the light chance of a thunderstorm over the hills on Wednesday.

That air feels a lot stickier than usual due to the easterly influence, but showers will be elusive.

The good news on the temperature front is that maximums will return to the high-to-mid twenties from Thursday onwards and remain in that range for at least four or five days.