Awnings in Bad Weather: What Each Type Can Handle in Rain, Wind, Snow, Hail, Heat and Lightning

How an awning copes with bad weather depends almost entirely on its type. A retractable fabric awning is built for sun: it can stay out in light rain if it is pitched steeply enough to drain, but it should be closed in winds around 20 to 25 mph (or whatever its manufacturer specifies), in heavy rain, and always before snow, hail or a thunderstorm. Fixed fabric awnings stay up in rain and moderate wind but are not snow structures unless designed for it. Rigid awnings in aluminum, steel or polycarbonate handle rain and wind well and can carry snow, but only to the load they were engineered for. No awning offers protection from lightning.

This guide is the overview for the Wind and Weather topic: a decision matrix first, then what each type of weather actually does to an awning, with the arithmetic behind the rules. Detailed guides cover snow, hail, hurricanes and storm preparation.

Decision matrix: what each awning type tolerates

Lightning is left out of the matrix because the answer is the same for every type: go indoors. An awning, metal or fabric, is not a lightning shelter.

Rain: pitch, ponding and how fast weight builds

Most awning fabrics shed water; the danger is water that cannot run off. A shallow pitch, a sagging middle or a gust that flattens the fabric creates a belly, and water is heavy: 1 inch of water weighs about 5.2 lb per square foot (62.4 lb per cubic foot divided by 12).

Rules that follow:

• Set the pitch to at least about 14 degrees if the awning might stay out in a shower, steeper in rainy climates. The projection and pitch guide shows the drop for each angle.
• Retract in heavy or sustained rain. Fabric that is "waterproof" still ponds; the difference between waterproof and water-resistant fabric is about leaks, not load (see the guide to waterproof vs water-resistant fabric).
• If you do retract wet, extend the awning to dry within a day or two to avoid mildew.

The full answer for retractables, including rain sensors, is in can retractable awnings stay out in rain, and the fixes for a fabric that keeps collecting water are in awning water pooling.

Wind: why the limit is lower than you expect

Wind pressure rises with the square of wind speed. The standard engineering relation for velocity pressure is about 0.00256 x V squared pounds per square foot, with V in mph, before any gust, shape or exposure factors.

Those raw forces look modest, but an awning turns them into leverage. On a 10 ft arm the force acts several feet from the bracket, and gusts arrive as repeated jolts that make fabric flog and arms bounce. Uplift is often worse than downward push, because a lateral-arm awning is designed to hang its weight down, not to resist being lifted. That is why most manufacturers say to retract retractable fabric awnings at sustained winds of roughly 20 to 25 mph or gusts approaching that, and why the limit should be treated as a ceiling, not a target.

The European standard EN 13561 tests external awnings into wind resistance classes 0 to 3, with higher classes tested to higher wind loads; a class figure is useful for comparing products but does not make a retractable safe in a storm. Ratings, the Beaufort scale and support legs are covered in awning wind ratings, and automatic retraction in wind and sun sensors. Fixed and rigid awnings depend on their anchors: a well-built aluminum awning on solid framing handles strong wind, while one screwed into siding alone does not.

Snow and ice

Snow is the one weather condition that can destroy a retractable awning without any wind at all. Fresh snow commonly weighs around 5 to 7 lb per cubic foot and wet snow 15 to 20 lb or more, so a few inches across a 120 sq ft canopy can add hundreds of pounds. Retractable awnings should be closed for the winter in snow regions and never extended over snow or ice. Fixed fabric awnings need their fabric removed unless the frame was designed for snow. Rigid canopies carry snow only up to their rated load in pounds per square foot, which must be compared with the local design value. Load math, sliding snow from the roof above and safe clearing are in the snow guide linked above; seasonal shutdown steps are in winterizing awnings.

Ice adds a second risk: fabric frozen to itself on the roller. Never run a motor or crank on a frozen awning; wait for a thaw, because forcing it can tear the fabric or overload the motor.

Hail

Small hail usually bounces off tensioned fabric. Hail of about 1 inch and larger (the National Weather Service threshold for severe hail) can tear older, UV-weakened fabric, dent thin aluminum and crack aged polycarbonate or acrylic sheet. Because hail arrives with thunderstorms that also bring damaging gusts, the response for a retractable is the same as for wind: retract early. What each material withstands, and how to document damage for insurance, is in the hail guide linked above.

Heat and intense sun

Heat rarely damages an awning in a single day, but it shapes long-term wear and a few short-term risks:

• UV over years. Sun exposure, not heat, is what fades and weakens fabric. Solution-dyed acrylic typically lasts about 8 to 15 years; coated polyester about 5 to 10.
• Hot surfaces. Dark aluminum and steel can get very hot to the touch in direct sun. Polycarbonate expands noticeably with temperature, which is why panels are fixed with slotted holes or expansion gaps.
• Motors. Tubular motors carry thermal protection that stops them after a few minutes of continuous running; repeated extend and retract cycles on a hot day can trip it. See awning motor overheating.
• Grills and fire pits. Most residential awning fabrics are not flame resistant. Keep grills, heaters and fire pits out from under the canopy and follow the manufacturer's clearance guidance; can you grill under an awning lists the distances by grill type.

Thunderstorms and lightning

The National Weather Service's guidance is blunt: no place outside is safe when thunder is heard, and open-sided structures such as porches, gazebos and picnic shelters do not protect you. An awning is no different. Practical points for owners:

• Retract before the storm arrives. The strongest gusts often come at the leading edge of a thunderstorm, before the rain, so waiting for the first drops is too late.
• Do not stand at a manual crank or hold a metal frame once thunder is audible.
• Motor controllers, sensors and smart hubs can be damaged by power surges. A surge-protected circuit is worth discussing with the electrician who wires a motorized awning.

A simple weather playbook

1. Know your awning's limits. Write the manufacturer's wind limit and pitch requirement on the inside of a cabinet door or in your phone notes.
2. Retract when you leave. Most damage to retractables happens when no one is home. Retract before leaving for the day and before bed unless a wind sensor is fitted and working.
3. Check the forecast for gusts, not averages. A forecast of 15 mph with gusts to 35 mph is a retract day.
4. Automate with care. Wind sensors help but react after a gust starts, and none detects snow or hail directly.
5. Inspect after severe weather. Look for bent arms, loose brackets, torn seams and standing water marks before the next extension.

Choosing an awning for a harsh climate

• Windy or coastal sites: a cassette retractable with a high wind class and a wind sensor, or a rigid aluminum awning anchored to framing. Salt air also calls for stainless hardware; see awnings in coastal environments.
• Heavy snow regions: a retractable that is closed all winter, or an engineered rigid cover with a stated snow load; avoid fixed fabric left up over winter.
• Frequent rain: a fixed or rigid cover if you want year-round use; a retractable only with steep pitch and the habit of retracting.
• Hail belt: retractables you can close quickly (a motor helps) or solid polycarbonate and heavier-gauge metal.

Frequently asked questions

Can I leave my retractable awning out in the rain?

In light rain, usually yes, if it is pitched at about 14 degrees or more so water runs off and does not pool. Retract it in heavy or sustained rain, in any wind approaching the manufacturer's limit, and when you leave home. An inch of standing water weighs about 5.2 lb per square foot, which retractable arms are not designed to carry.

At what wind speed should I retract my awning?

Most manufacturers advise retracting fabric retractable awnings in sustained winds of roughly 20 to 25 mph, or when gusts approach that level, and some set a lower figure. Follow your awning's own rating. Wind force rises with the square of speed, so a 40 mph gust pushes about two and a half times harder than a 25 mph wind.

Can an awning stay up in winter?

A retractable awning can stay mounted in winter if it is fully retracted, ideally into a hood or cassette, and automatic extension is switched off. Fixed fabric awnings in snowy areas should have their fabric removed unless the frame is snow rated. Rigid metal or polycarbonate awnings can stay up if their rated snow load meets local requirements.

Is it safe to stand under an awning during a thunderstorm?

No. The National Weather Service advises that no outdoor location is safe when thunder can be heard, and open-sided structures such as porches and shelters do not protect against lightning. Go inside a fully enclosed building or a hard-topped vehicle, and retract the awning before the storm arrives rather than during it.

Do wind sensors protect an awning from all bad weather?

No. Wind or motion sensors retract the awning when movement or wind speed passes a threshold, so they react after gusts begin. They do not detect snow or hail, and a rain sensor only responds once rain starts. Sensors also fail if batteries die or power is cut. Treat them as a backup to retracting it yourself.

Sources and further reading

• National Weather Service: Lightning Safety (including "When Thunder Roars, Go Indoors")
• NOAA National Severe Storms Laboratory: Severe Weather 101, Hail
• American Society of Civil Engineers: ASCE 7, Minimum Design Loads and Associated Criteria for Buildings and Other Structures (wind and snow loads)
• CEN: EN 13561, External blinds and awnings, performance requirements including safety
• Federal Emergency Management Agency: Snow Load Safety Guide