The three-color low-temperature advisory is based on the lowland minimum temperature: yellow is 10 degrees Celsius or below; orange is 6 degrees or below, or 10 degrees or below with 24 consecutive hours at 12 degrees or below; red is 24 consecutive hours at 6 degrees or below. The "cold surge" (寒流) in the news follows a separate standard: it counts as a cold surge only when the minimum at the Taipei station falls to 10 degrees or below; 10 to 12 degrees is a strong continental cold air mass (強烈大陸冷氣團), and 12 to 14 degrees is a continental cold air mass (大陸冷氣團).
Reminder: The Central Weather Administration (CWA) puts the same sentence in the notes for all three advisory colors: pay attention to indoor ventilation and electrical safety when using gas water heaters and electric heaters. Do not install a gas water heater on an enclosed balcony, do not plug an electric heater into an extension cord, and do not use an electric heater that is not designed for bathrooms inside the bathroom. For installing or relocating a water heater, use a qualified licensed gas installation contractor (瓦斯承裝業者).
Official definitions of the low-temperature advisory colors
The CWA's low-temperature advisory page and its advisory color explanatory document list the same standard. Advisories are issued by county and city, with township-level colors attached. "Lowland" means areas at an elevation of 200 meters or below, and a county's color is the most severe color among its lowland areas. This grading was set in 2019 after discussion among what was then the Central Weather Bureau, related ministries and county and city governments, and took effect on 1 November 2019; township-level colors have been added since late 2022.
| Color | Standard | Summary of CWA notes | Basis |
|---|
| Yellow (cold) | Lowland minimum temperature 10°C or below | Mornings and evenings are cold. Watch for staying warm and for day-night temperature swings; take care with ventilation and electrical safety for gas water heaters and electric heaters; watch for respiratory and cardiovascular illness; look out for older people and vulnerable groups. | CWA low-temperature advisory page |
| Orange (very cold) | Lowland minimum temperature 6°C or below, or lowland minimum 10°C or below with lowland temperatures at 12°C or below for 24 consecutive hours | The weather is very cold. Keep warmer; avoid staying in the cold for long periods; make sure children's heads, necks, hands and feet are kept warm; practice hand hygiene during flu season. | CWA low-temperature advisory page |
| Red (severe cold) | Lowland temperature at 6°C or below for 24 consecutive hours | Severe cold; take strict precautions. Take strong measures against the cold; pay more attention to older people, homeless people and vulnerable groups; the farming and fishing sectors should take necessary measures to reduce losses. | CWA low-temperature advisory page |
A few details are often overlooked. Because of its latitude and geographic climate, Lienchiang County (連江縣) uses thresholds 4 degrees lower than the table above. For townships without a weather station, the color is estimated from observations at neighboring townships. Colors for mountain townships are provided after lowland townships in the same county reach the threshold, with reference to the climate of neighboring lowlands, so mountain colors are for reference only. While an advisory is in effect it is updated at about 4:30, 6:30, 10:30, 16:30 and 22:30 (24-hour clock); at other times, check observation data for the actual temperature. This site's Taiwan weather by county and city page also shows live conditions for each county and city.
Cold surge, strong continental cold air mass and continental cold air mass: how they differ
These three terms are the CWA's grading of "cold air strength", and they are a separate system from the low-temperature advisory. As the CWA's popular-science website (氣象署數位科普網) explains: Taiwan uses the lowest temperature recorded in Taipei City as the measure of cold air strength, in three grades. The climate encyclopedia (氣候小百科) on the CWA's climate information portal (氣候服務入口網) also states that a cold surge is defined as the Taipei station reaching a temperature of 10 degrees or below at any point in time.
| Name | Lowest temperature in Taipei City | Basis |
|---|
| Cold surge (寒流, also called 寒潮) | Falls to 10°C or below | CWA popular-science website, climate encyclopedia |
| Strong continental cold air mass (強烈大陸冷氣團) | Between 10°C and 12°C (12°C included) | CWA popular-science website |
| Continental cold air mass (大陸冷氣團) | Between 12°C and 14°C (14°C included) | CWA popular-science website |
The difference between the two standards is "where they look". The cold surge definition looks only at the Taipei station; this article reads it as a nationwide label for cold air strength. The low-temperature advisory looks at each county's own lowland minimum and is a local warning. As this article's own example, two situations are possible: Taipei at 11 degrees does not reach cold surge level, but Hsinchu and Miaoli lowlands are already at 9 degrees and show yellow; or Taipei meets the cold surge standard while Kaohsiung is only at 14 degrees and has no advisory. This article's suggestion: to know whether your own home will be cold, the low-temperature advisory color is a better guide than the words "cold surge". The CWA's explanation of air masses also notes that when a continental cold air mass originating in Siberia moves south to Taiwan in winter, temperatures often drop sharply within 24 to 48 hours.
Why cold surges still happen in a warm winter, and where it is coldest
The CWA's climate encyclopedia explains that a "warm winter" (暖冬) means the average temperature over the whole winter (December, January and February) is higher than the climate average, a long-term measure, while a "cold surge" is a short-term event that holds as soon as the Taipei station falls to 10 degrees or below at any point. In a warm winter, each wave of cold air can still break below 10 degrees, so the two do not conflict.
Low temperatures also follow a pattern in where they occur. The CWA's advisory color explanatory document says: when cold air moves south, the north and northeast bear the brunt first and the largest temperature drop is along the coast, while radiative cooling affects open areas, areas near mountains and the Hualien-Taitung rift valley. Lowland areas of the main island that often see low temperatures are Taoyuan, Hsinchu and Miaoli, Keelung and the north coast, and the northeast coast (東北角); areas near mountains in Greater Taipei, Nantou and Chiayi, and the Hualien-Taitung rift valley, also often get cold from radiative cooling. In general weather knowledge these two mechanisms are called advective cooling and radiative cooling, and when they combine, the clear-sky early mornings after a cold surge passes are the most likely time for extreme lows. This article's reminder: if you live near mountains or the coast, the township color is a better guide than the county color.
When a low-temperature advisory is lit, what to watch at home
The only CWA note directly related to the home is one sentence: pay attention to indoor ventilation and electrical safety when using gas water heaters and electric heaters. The points below break that sentence into concrete actions; this site already has detailed articles on each, so only key points and links are given here.
- Gas water heaters: During a cold surge, showers are longer and doors and windows are shut tight, so the risk of carbon monoxide poisoning rises (this article's summary). For where a water heater should be installed and whether to switch to a forced-exhaust model, see the water heater typhoon-proofing, exhaust and ventilation safety guide; for where to put carbon monoxide alarms and how many, see where to install carbon monoxide alarms.
- Electric heaters: For adding up wattage, whether an extension cord can be used, and whether a heater can be used in the bathroom, see what to do when an electric heater trips the breaker and how to calculate extension cord load in watts. For a comparison of electricity use between air conditioner heating mode and electric heaters, see choosing home heating in Taiwan.
- Hot water pipes: When sharp cold snaps alternate with warmer spells, hot water pipe joints in older homes tend to leak; see preventing hidden pipe leaks from thermal expansion and contraction in cold snaps.
- Going out: At orange and above, the CWA advises avoiding staying in the cold for long periods. For what to wear on your commute and whether to bring an umbrella, use the commute outfit and umbrella decision helper.
Does a cold surge mean work and school closures?
In principle, no. Q&A Q2-5 in the Directorate-General of Personnel Administration's operating Q&A (行政院人事行政總處; May 2026 revision) explains that under Article 8 of the natural disaster work and class suspension regulations (天然災害停止上班及上課作業辦法), work and class suspension may be announced only when another natural disaster interrupts or disrupts transport, water or electricity supply, affects the safety of travel, work or classes, or risks causing a disaster or requires evacuation; for low-temperature cold damage, the authority responsible for announcing suspensions may announce one only when these circumstances are met. Low temperature alone is not a reason for a work and class suspension (停班停課). For the complete rules on suspensions, see how typhoon days off are decided.
Frequently asked questions
Which is colder, a yellow low-temperature advisory or a cold surge?
They cannot be compared directly. Yellow is a county's lowland minimum of 10 degrees or below, and a cold surge is the Taipei station at 10 degrees or below. The threshold number is the same but the location differs: yellow looks at any station in that county's lowlands, while a cold surge looks only at the one Taipei station. When Miaoli shows yellow, Taipei may be at only 12 degrees, and the news would then mention only a strong continental cold air mass.
How is "12 degrees or below for 24 consecutive hours" counted?
The second condition for orange is a lowland minimum of 10 degrees or below, and lowland temperatures staying at 12 degrees or below for 24 consecutive hours, meaning it does not warm up even during the day. The CWA says the colors are graded by the "degree and duration" of the low temperature, and duration is the main thing that separates orange and red from yellow.
What time is the low-temperature advisory updated?
The CWA's low-temperature advisory product description states that, during the issuing period, it is updated daily at 4:30, 6:30, 10:30, 16:30 and 22:30 based on the latest observation and forecast data. The Q&A in the color explanatory document also mentions that when a forecast cold air mass, cold surge or marked radiative cooling will bring low temperatures over a fairly wide area from that night into the next day, the CWA issues colors in the morning based on the forecast low temperatures for each county.
There are no weather stations in the mountains. Where do the colors come from?
The Q&A in the CWA's color explanation states: when a township has no weather station, a reasonable scientific estimate is made from observations at neighboring townships; colors for mountain townships are provided after lowland townships in the same county reach the threshold, taking into account the climate of neighboring lowlands, for reference. Actual temperatures in the mountains are usually lower, so adjust accordingly.
Last updated: 2026-10-30
This article was compiled by SOSfix editors from public information and is for general reference only; for individual cases, consult the Central Weather Administration, your county or city government, or a qualified gas and plumbing/electrical technician.
Sources
- Central Weather Administration: low-temperature advisory page, "Low-temperature advisory color content" (verified 2026-10-30; in Chinese): full text of the yellow, orange and red standards and notes for each color; lowland means elevation 200 meters or below, Lienchiang County minus 4 degrees, county color takes the most severe lowland color, update times.
- Central Weather Administration: low-temperature advisory color explanation and Q&A (PDF, URL version tag v=20221124; in Chinese): took effect 1 November 2019, township colors since late 2022, areas that often see low temperatures, how colors are set for townships without stations and for mountain townships, timing of issuance.
- Central Weather Administration product description: low-temperature advisory (last modified 2026/01/06, PDF; in Chinese): issued by county and city with township colors added, five update times a day.
- Central Weather Administration popular-science website (氣象署數位科普網): the little leopard cat's cold surge question (verified 2026-10-30; in Chinese): graded by the lowest temperature in Taipei City; cold surge 10 degrees or below, strong continental cold air mass 10 to 12 degrees (12 included), continental cold air mass 12 to 14 degrees (14 included).
- Central Weather Administration climate information portal (氣候服務入口網), climate encyclopedia (氣候小百科): do cold surges still occur in a warm winter? (2024-01-23; in Chinese): a cold surge is defined as the Taipei station at or below 10 degrees at any point in time; a warm winter is a winter average above the climate average.
- Central Weather Administration weather knowledge: question 3, "air masses?" (in Chinese) and question 2 (advective cooling and radiative cooling; in Chinese): temperatures drop sharply within 24 to 48 hours after a continental cold air mass moves south; advective and radiative cooling combine to produce extreme lows.
- Directorate-General of Personnel Administration: natural disaster work and class suspension operating Q&A (revised May 2026, PDF attachment; in Chinese): Q2-5, conditions for work and class suspension for low-temperature cold damage.
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