Beach Warning Flags: What Each Color Means

On beaches that use the common warning flag system, double red means the water is closed, red means high hazard, yellow means medium hazard, green means low hazard (but still take care) and purple means dangerous marine life. Flag systems are not the same everywhere, so always read the sign at the beach entrance and ask the lifeguard what today's flag means.

Flags are a quick way for lifeguards to tell a whole beach what the water is doing. This guide explains the common colors, where they differ, and how to use them with the forecast and the lifeguard.

The common flag colors

The National Weather Service (NWS) office in Tallahassee, Florida, describes the flags used along its stretch of the Gulf Coast. These are the colors most U.S. visitors will see:

Source: NWS Tallahassee, Rip Current Awareness (opens in a new tab).

Red and double red

Double red. The NWS says double red flags mean the water is closed and you could be arrested or fined (opens in a new tab) for entering the water. This is not a suggestion. Stay on the sand.

Single red. The NWS says a single red flag means a high hazard with high surf and/or strong currents (opens in a new tab). What a single red flag allows can differ from beach to beach, so ask the lifeguard. If you're unsure, stay out.

Red flags can also mean something more specific at some beaches:

• NYC Parks beaches: closed sections are marked with signs and/or red flags (opens in a new tab), and swimming is not allowed in them.
• Gateway National Recreation Area (including Jacob Riis Park in Queens and Great Kills Park on Staten Island): the National Park Service says red flags mean no lifeguards on duty and no swimming or wading (opens in a new tab).

Yellow, green and purple

Yellow. The NWS says a yellow flag means a medium hazard with moderate surf and/or currents (opens in a new tab). Keep children within arm's reach and stay where the lifeguard can see you.

Green. The NWS says a green flag means a low hazard with calm conditions, but it's still wise to exercise caution (opens in a new tab). Green is not a promise. The NWS forecast offices say that even when the rip current risk is low, life threatening rip currents often occur in the vicinity of groins, jetties, reefs, and piers (opens in a new tab).

Purple. The NWS says a purple flag will sometimes fly with the other flags (opens in a new tab) and means dangerous marine life is in the water. A purple flag can fly next to a green or yellow one.

Why flags vary by beach

The NWS is clear that warning flags aren't used in all areas and their meaning can vary from area to area (opens in a new tab). So before you trust a color:

• Read the sign at the beach entrance. The NWS says to read the beach safety signs at the entrance to the beach (opens in a new tab), then look for flags, often posted on or near a lifeguard's stand.
• Check where the flags are. Some beaches fly flags at each access point. Jacksonville Beach, Florida, for example, says flags may be flown by beach accesses or on the beach in specific locations (opens in a new tab).
• Look for other signs. In New York City, the Health Department posts its own water-quality signs: a yellow sign means swimming and wading not recommended (opens in a new tab), and a red sign means swimming and wading are not allowed. These are about pollution, not waves.
• Ask a lifeguard if anything is unclear.

Conditions also change during the day. The NWS says rip currents on many beaches often flow faster about an hour or two on either side of low tide (opens in a new tab), and that hurricanes that are far away can still create deadly rip currents and waves (opens in a new tab). Look at the flag every time you go back in the water.

Flags don't replace a lifeguard's advice

A flag is a summary. A lifeguard can tell you the details: where the rip currents are today, which section is calmest, and whether the tide is about to change things.

• The NWS says to check the beach forecast before you leave and talk to the lifeguard at the beach (opens in a new tab).
• The Red Cross says to check whether any warning flags are up (opens in a new tab) and ask a lifeguard about water and beach conditions.
• The NWS beach forecast advice for every rip current risk level ends the same way: always swim near a lifeguard and remember to heed the advice of the local beach patrol and flag warning systems (opens in a new tab).

Flags also don't tell you about you. A yellow-flag day might be fine for a strong ocean swimmer and dangerous for a child who has only swum in pools. Read more in why swimming near a lifeguard matters and how to spot and escape a rip current.

Teach kids the colors

Turn flags into a game on the drive to the beach: "Red means?" "Stay out!" Our guide to teaching kids ocean safety has more ideas, and the Beach Flag Match game on our kids' site lets them practice.

What you can do today

1. Try the Beach warning flags decoder decoder so the colors are familiar before your trip.
2. Print the Beach Warning Flags and keep it in the car or beach bag.
3. Look up your beach's own flag key on its official website before you go. If you're in New York City, start with NYC beach safety.
4. Add "check the flag" to your beach routine, along with the forecast and a word with the lifeguard. Our family beach safety checklist has the full list.