May weather forecast
Houston, TX

May brings in the official start of summer in Houston. The city shimmers under the hot sun and becomes bustling with a range of summer activities. May is a festive time in Houston, with several outdoor festivals and concerts that take advantage of the fine weather. Being midway through spring and the onset of summer, May breaks the rainfall record with a whopping 4.45" (113mm). This underlines the typical late spring weather pattern in Houston which melds higher humidity with increased rainfall.

Temperature

As Houston welcomes May, the average high-temperature sees a modest rise, transitioning from a warm 78.8°F (26°C) in April to a still moderately hot 85.8°F (29.9°C). In Houston, May nights witness a steady temperature drop to an agreeable 70°F (21.1°C).

Heat index

The average heat index in May is estimated at a torrid 96.8°F (36°C). Additional precautions are required to avert heat cramps and heat exhaustion. Persistent activity may culminate in heatstroke.
It is noted that heat index values are ascertained for locations in the shade and with gentle breezes. The heat index may experience an enhancement of 15 Fahrenheit (8 Celsius) degrees under direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is the outcome of merging air's temperature and its humidity metrics. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
One of the main methods the human body employs to cool down is by perspiring, as this process allows sweat to evaporate and remove excess heat. Under high air temperature coupled with high humidity (high heat index), the body's perspiration is reduced, intensifying the sensation of heat. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.

Humidity

The average relative humidity in May is 74%.

Rainfall

In Houston, Texas, in May, during 14.8 rainfall days, 4.45" (113mm) of precipitation is typically accumulated. In Houston, Texas, during the entire year, the rain falls for 180.5 days and collects up to 35.35" (898mm) of precipitation.

Snowfall

In Houston, snow does not fall in February through November.

Daylight

In Houston, the average length of the day in May is 13h and 40min.
On the first day of the month, sunrise is at 6:38 am and sunset at 7:58 pm. On the last day of May, sunrise is at 6:21 am and sunset at 8:17 pm CDT.

Sunshine

The average sunshine in May in Houston, Texas, is 9.3h.

UV index

May through August, with an average maximum UV index of 7, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: In May, the average maximum UV index of 7 translates into the following recommendations:
Deflect overexposure. Sun protection is a necessity. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.