Chennai is set for a bright, sunny, and warm day on Wednesday, January 21, 2026, with temperatures expected to reach 27.4°C and dip to 19.9°C at night.However, air quality remains a concern, as yesterday’s pollution was categorized as “poor” and may persist into today, particularly during peak traffic hours.While rain is not anticipated, residents are advised to consider wearing masks near busy roads and to plan outdoor activities during the cooler parts of the day.The forecast for the upcoming week indicates mostly sunny conditions, with a brief period of patchy rain expected on January 26.
Wednesday’s Weather Details
The day in Chennai on Wednesday, January 21, 2026, begins with a bright and summery feel.The forecast indicates largely sunny skies throughout the day.Temperatures are projected to climb to approximately 27.4°C during the day.The night will see temperatures dipping to 19.9°C, ensuring warmth without being oppressive.The daily temperature range is considered comfortable by Chennai standards.The high for today is 27.4°C, while the low is 19.9°C.This results in an average temperature of around 23.4°C for the day.Humidity is expected to average 66 percent.This level of humidity may lead to a slightly sticky sensation in the afternoon.Skies are anticipated to remain largely clear despite the humidity.Winds are forecast to pick up to approximately 20.2 kilometers per hour.These winds can help to mitigate the warmth, especially in open coastal areas and along wider roads.Rain is barely on the radar for today.Total precipitation is measured at just 0.02 millimeters.A 0 percent chance of rain is indicated for the day.This allows for planning without the uncertainty of whether it will rain.“will it, won’t it”With the clear and sunny conditions, the day is expected to feel most comfortable from late morning into early afternoon.The coolest and easiest outdoor window is typically around sunrise.Another comfortable period for outdoor activities is after sunset.For specific timings, Chennai will experience sunrise at 6:36 AM today.Sunset is scheduled for 6:05 PM.This golden-hour stretch can be utilized for errands or longer commutes, avoiding the harsh midday glare.
Air Quality Concerns
Yesterday, Tuesday, January 20, Chennai recorded an Air Quality Index (AQI-IN) of 219.This reading was classified as “Poor”, falling into category 4.The US AQI equivalent for the same day stood at 182.This also indicated unhealthy conditions for many individuals.Particulate matter was identified as the primary concern.PM2.5 levels were recorded at 98.PM10 levels were measured at 118.Both these levels are considered high enough to cause irritation.Carbon monoxide (CO) was measured at 497, contributing to the overall pollutant load.These levels of particulate matter are sufficient to “irritate the eyes and throat and to aggravate asthma or allergic rhinitis”.Regarding today’s air quality, sunny weather and steady winds are factors that “can help disperse pollutants a bit”.This dispersion is more likely to occur during the day.However, morning and late-evening periods often present a challenge.During these times, emissions are “often trap emissions closer to the ground”.For individuals sensitive to air quality, the safest approach is to keep outdoor exercise light.Such activities should be timed for periods when traffic is lower.
Precautions for the Day
To plan the day effectively, several considerations are important.The sun will be strong even in January.Sunglasses and sunscreen are recommended, particularly if spending time outdoors after 11 AM.Since rain is not expected, an umbrella is not necessary.However, keeping water handy is advisable, as humidity can lead to quiet dehydration.Given yesterday’s air quality, which was classified as “poor”, specific precautions are suggested.A well-fitting mask should be considered for long two-wheeler rides.It is also recommended for those waiting at bus stops or navigating traffic-heavy corridors.Families with children, older adults, and individuals with respiratory issues should prioritize indoor workouts today.Alternatively, they could choose quieter parks located away from main roads.
The Week Ahead
The outlook for the week ahead indicates largely stable and bright conditions.January 22 and January 23 are expected to remain sunny.High temperatures will be near 27.4–28.1°C, with nights around 19.8–20.7°C.These conditions are favorable for outdoor plans.January 24 and January 25 will see partly cloudy skies.Despite the cloud cover, the days are expected to remain dry and warm.Highs will be around 28.4°C.Nighttime temperatures will also rise slightly, reaching up to 22.3°C by January 25.One day to monitor closely is January 26.This day is forecast to bring patchy rain to the vicinity.It represents the week’s “clearest wet signal”.Approximately 0.59 millimeters of rain are expected, with an 88 percent chance of precipitation.Higher humidity, around 76 percent, is also anticipated on this day.If travel or an outdoor event is planned, January 23 to January 25 appear to be the “easiest” days.January 26 is the “day to keep buffer time and carry light rain protection”.Conditions are expected to return to sunny on January 27.A warmer high temperature near 29.1°C is forecast for this day.A bonus note highlights recent trends in air quality.Air quality has been “stubborn lately—yesterday’s “poor” reading follows several “moderate” days and even a “poor” spike earlier in the week (AQI-IN 231 on Jan 14)”.Therefore, it is prudent to monitor daily AQI updates.This is recommended even when the sky appears clear.The data referenced in this article is taken from AQI.in.
