SmogRank / United States / California / South Lake Tahoe

South Lake Tahoe, month by month

South Lake Tahoe has a measured daily mean on 889 days since 22 May 2023. Its worst month was March 2026, at 95 US AQI (32.5 µg/m³), 214th of 2,971 cities on that month's world ranking. Its cleanest was February 2024, at 7 US AQI (1.3 µg/m³).

Every month since 2023

202654 so far223 days measured888th of 2,791 in the world
Jan47#1,358Feb12 daysMar95#214Apr33#2,210May38#1,681Jun44#1,073Jul14 daysAug21 daysSep39#1,272Oct45#965
2025too few days for a mean (a year needs 256)242 days measured
Jan35#1,911Feb35#2,037Mar20 daysApr6 daysMay42#1,478Jun17 daysJul13 daysAug46#1,720Sep14 daysOct32#1,732Nov9 daysDec34#2,428
2024too few days for a mean (a year needs 257)250 days measured
Jan18#2,336Feb7#2,483Mar11 daysAprnoneMay3 daysJun20 daysJul52#891Aug21 daysSep47#730Oct36#1,342Nov32#2,112Dec41#1,576
2023too few days for a mean (a year needs 256)174 days measured
JanFebMarAprMay10 daysJun36#1,268Jul4 daysAug12 daysSep33#1,808Oct34#1,455Nov27#1,997Dec30#1,955
Each square is a month's mean PM2.5 in US AQI from South Lake Tahoe's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with South Lake Tahoe marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

17 months
MonthWhy
Aug 202621 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 202614 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Feb 202612 of 28 days measured; a month needs 20. The others: 16 with under 18 hours of readings or readings that failed our checks.
Nov 20259 of 30 days measured; a month needs 21. The others: 21 with under 18 hours of readings or readings that failed our checks.
Sep 202514 of 30 days measured; a month needs 21. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jul 202513 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Jun 202517 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Apr 20256 of 30 days measured; a month needs 21. The others: 24 with under 18 hours of readings or readings that failed our checks.
Mar 202520 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Aug 202421 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jun 202420 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
May 20243 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Apr 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 202411 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 19 with under 18 hours of readings or readings that failed our checks.
Aug 202312 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jul 20234 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 26 with under 18 hours of readings or readings that failed our checks.
May 202310 of 31 days measured; a month needs 22.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

South Lake Tahoe's worst months

MonthUS AQIDays measuredWorld rank
March 2026 9532.5 µg/m³29 of 31214thof 2,971
July 2024 529.4 µg/m³30 of 31891stof 2,566
January 2026 478.5 µg/m³31 of 311,358thof 2,617
September 2024 478.4 µg/m³30 of 30730thof 2,010
August 2025 468.3 µg/m³28 of 311,720thof 2,901
June 2026 448.0 µg/m³22 of 301,073rdof 2,497

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

South Lake Tahoe's worst days

DayUS AQI
4 Jan 2026 15256.5 µg/m³
3 Mar 2026 13147.6 µg/m³
6 Mar 2026 13147.6 µg/m³
5 Mar 2026 12846.5 µg/m³
4 Mar 2026 12846.3 µg/m³
9 Mar 2026 12746.0 µg/m³
7 Mar 2026 12645.8 µg/m³
8 Mar 2026 12645.5 µg/m³
11 Mar 2026 12445.0 µg/m³
12 Mar 2026 12445.0 µg/m³

Daily means, the highest since 22 May 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, South Lake Tahoe, United States, 22 May 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/south-lake-tahoe/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

South Lake Tahoe now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 20:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).