WEATHER BLOG: Why is the temperature in my house different?

WEATHER BLOG: Why is the temperature in my house different?

TAMPA, Fla. – I get this question often, especially this time of year … why is the temperature in my home different from the one you show on Spectrum Bay News 9?

The answer is because we have microclimates in our region, where temperatures can vary largely over a very short distance. Many regions across the country experience ‘microclimates’, but due to our unique location between the Atlantic Ocean and the Gulf of Mexico, we tend to have even more variation in temperature.

When cooler, drier air comes in from the north in winter, it can feel more like Georgia here rather than South Florida.

Have you ever noticed how our morning depths are where the biggest differences are? It can almost freeze in some places, while it is in the 50’s … all on the same morning! The reason for this is that the colder air in low-lying areas far from the coast can ‘get stuck’. So at night after the sun’s heat radiates off the ground, the cold air remains, resulting in cold morning depths.

This is called ‘radiation cooling’. This cold air tends to always settle in the same places due to the unique orographic layout of our area. For example, there are hills combined with low-lying valleys that stretch from Citrus, Hernando, and Pasco County all the way to the east of Hillsborough and the west of Polk County. This tends to act as a funnel for the cold air to settle in those areas. It is just close to the I-75 corridor.

You’ve probably seen us talk about these ‘colder’ areas several times. Some of the coldest locations are usually located near Inverness in Citrus County, Brooksville in Hernando County, Zephyrhills in Pasco County, and Brandon-Valrico in Hillsborough County.

If you draw a line on the map between those locations, you get an idea of ‚Äč‚Äčthat colder funnel area I’m referring to. This is clearly visible in the attached images on this page.

Locations near the coast are usually milder due to the influence of the warmer Gulf waters. Locations around the bay are milder for the same reason. The interesting thing is that the temperature can drop quickly a few kilometers from the water. We’ve seen locations in northern Pinellas County between Clearwater and East Lake sometimes get 15 degrees colder than Clearwater Beach.

It is clearly warmer on the water in places like downtown St. Pete and Bradenton, but temperatures can be drastically cooler further inland. Locations just east of I-75 between Sun City Center, Parrish and Lakewood Ranch are known to be much cooler on winter evenings.

In Polk County, temperatures can be greatly influenced by the many lakes. One of the best known examples is the Winter Haven meter on the west side of the regional airport. It is surrounded by 5 lakes! Because of this very interesting location, the meter is often much warmer than other locations in the county, as the lakes tend to act like a warming blanket around the airport.

However, other locations like Polk City, Lake Wales, Mulberry, Kathleen and the west side of Lakeland are all cooler. Something very interesting is also the Mid-Florida Ridge (also called the Lake Wales Ridge) which runs through the east of Polk County. This ridge sometimes functions as an orographic boundary for cold air to stay west of it, causing large temperature swings in Polk County.

In winter we talk a lot about these differences. If you look at our weather forecast at: 19 minutes past the hour, you will notice that we always provide a forecast by province. Here we show you more detailed forecasts and those differ at the local level.

If you just quickly tune into our station and see a temperature on the corner of the screen and wonder why your meter is different from that number, you now know why.

This is also a good time to remind everyone that if you notice different temperatures in your phone app, it shows the limitations of automated phone apps compared to a real human prediction. As a meteorologist, it is my job to understand, explain and predict these variations for our region.

Unfortunately, with the advent of phone apps, a lot of incorrect weather information is floating around. A weather app is intended to give a general idea and can be a good starting point for basic information, but is not intended to be the complete source of accurate information.

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