Climatology of a Fall Freeze/Killing Freeze (2024)

FAQs

Climatology of a Fall Freeze/Killing Freeze? ›

A freeze will occur when temperatures reach or fall below 32 degrees. While some plants are able to with stand a brief period at or just below 32 degrees, most plants will not survive once temperatures drop to or below 28 degrees (often refer to as a killing freeze).

A "killing frost" is now considered to be a temperature of 28°F in the United States, but in 1916, the type of frost was determined by the level of damage incurred.

HOUSTON – When the temperature drops to 24° or below for two hours or more, that is considered a “hard” freeze. That is most dangerous to pipes freezing (and don't forget pool pipes!).

NWS issues a hard freeze warning when temperatures are expected to drop below 28°F for an extended period of time, killing most types of commercial crops and residential plants. Freeze Warning: Take Action!

A frost occurs when the temperature at ground level falls to 0°C, however most temperate plant species will tolerate this and it is not until temperature falls below -2°C when water moves out of the plant cells resulting in death and desiccation of the tissue.

A moderate frost, with temperatures ranging from about 28°F to 32°F, necessitates a bit more precaution. In addition to tucking your plants in well with some frost cloth or cover, it's also a good idea to water your plants the evening before frost is expected to hit.

Covering plant material at temperatures between 39-30 with freeze cloth or covering can be effective. Prolonged exposure at temperatures of 28 degrees and below will notice protection results diminish with each degree dropped.

Frost becomes more widespread when the temperature falls below 32°F with some freeze possible. A hard freeze is possible when temperatures fall below 28°F.

A hard freeze is anything within the range of 28 - 25 degrees. A freeze this severe this destructive to most all our crops.

Generally, a “freeze” happens anytime temperatures drop to 32 degrees or lower. But to be considered a “hard” freeze, temperatures must drop to at least 28 degrees and stay there for a significant amount of time, usually at least a few hours. POLAR PLUNGE: A hard freeze is coming to Texas next week.

What temperature do pipes freeze at? ›

Your pipes are at risk of freezing any time temperatures drop below 32°F. However, it's much more common for pipes to freeze when temperatures dip below 20°F. The longer the weather remains below freezing, the more likely it is your pipes can freeze if not properly protected and winterized.

The biggest danger of driving in freezing temperatures is the build up of black ice. As its name implies, this type of ice can appear black and blend in with the dark pavement. Whether you are driving during the day or at night and on back roads or the highway, you can easily miss a patch of black ice on the road.

Thus, frost can form even when a thermometer gives a reading in the upper 30s. Since official weather measurements are taken in an instrument shelter four to five feet above the ground, frost can form even when the official temperature is above freezing. (Related: measuring weather).

A freeze happens when air temperature dips below 32°F. The colder it gets, the more damage you'll see to annual and perennial plants. A hard freeze is usually between 28-25°F, and a killing freeze is 24 degrees F and below.

Perennial Flowers: Most perennial plants do not suffer frost damage and do not need to be covered. Frost sensitive perennials include Hostas and Bleeding Hearts. They should be covered to protect their foliage and flowers. Cover any blooming or budded up perennials.

You can also use cardboard boxes to add a layer of insulation when container gardening if you're worried about potted plants at risk of frost. Simply invert a cardboard box over the top and weigh down the flaps to make it secure. So the answer is yes, cardboard boxes will protect plants from frost.

A local study done on frost formation relating temperature to dew point has these guidelines for frost: temperatures from 38 to 42 F can lead to patchy frost, 33 to 37 areas of frost, and 32 and below widespread frost/freeze.

Q: Can frost occur at temperatures above 32°F? A1: No, frost is defined as a layer of ice that forms on surfaces that are at or below 32°F.

A freeze happens when air temperature dips below 32°F. The colder it gets, the more damage you'll see to annual and perennial plants. A hard freeze is usually between 28-25°F, and a killing freeze is 24 degrees F and below.

At temperatures below 32°F (0°C), liquid water freezes; 32°F (0°C) is the freezing point of water. At temperatures above 32°F (0°C), pure water ice melts and changes state from a solid to a liquid (water); 32°F (0°C) is the melting point.