Welby, Colorado, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
February Air Quality Analysis
Welby, Colorado, United States
AQI Trends: Highest and Lowest
Same Day Analysis (18th February):
On this day, AQI across the 5 years varied significantly: 2026 ranks the most lowest AQI at 22 of Good air quality, showing improvement over 2025, 2024, 2023 and 2022 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 17th Feb - 18th Feb 2026
Welby, Colorado, United States
7 AM17th Feb 2026
5 PM
6 AM18th Feb 2026
66AQI
17AQI
38AQI
9AQI
In the last 24 hours,
Welby's AQI reached its highest point of 66 at 12 PM during the Day, while the lowest point, 9, was recorded at 2 AM during the Night between 17th Feb and 18th Feb 2026.
Day & Night AQI Trend : Jan - Feb 2026
Welby, Colorado, United States
2°C-3/13°C
2°C-5/11°C
-2°C-8/4°C
-8°C-12/-6°C
-10°C-14/-6°C
-9°C-12/-3°C
-3°C-13/8°C
1°C-3/9°C
1°C-6/6°C
2°C-2/6°C
3°C-3/11°C
5°C-3/15°C
7°C0/17°C
6°C0/12°C
3°C-1/9°C
4°C-3/13°C
9°C0/19°C
9°C2/18°C
8°C0/17°C
11°C4/20°C
10°C3/22°C
5°C1/9°C
6°C-2/15°C
7°C2/13°C
7°C1/13°C
7°C2/14°C
9°C0/19°C
9°C2/18°C
9°C4/14°C
4°C-2/11°C
45AQI
25AQI
36AQI
21AQI
2026 Days Vs Air Quality
Welby, Colorado, United States
100%
49
Total number of days with different AQI categories in last 50 days in 2026 (315 days remaining)
Under WHO’s Safe Air Quality Limits: 100%
Health Risk Level:
Very Low
In 2026, 100% of 50 days were within WHO’s safe air quality limits. The risk of health issues is Very Low, but health impacts are still unclear.
Annual Air Quality Insights
Welby, Colorado, United States
AQI levels in 2026
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
22AQI (US)
23AQI (US)
32AQI (US)
16AQI (US)
42AQI (US)
19AQI (US)
43AQI (US)
18AQI (US)
25AQI (US)
22AQI (US)
18AQI (US)
28AQI (US)
25AQI (US)
21AQI (US)
28AQI (US)
28AQI (US)
14AQI (US)
15AQI (US)
19AQI (US)
27AQI (US)
26AQI (US)
32AQI (US)
26AQI (US)
31AQI (US)
23AQI (US)
20AQI (US)
23AQI (US)
39AQI (US)
38AQI (US)
38AQI (US)
26AQI (US)
24AQI (US)
48AQI (US)
38AQI (US)
28AQI (US)
38AQI (US)
31AQI (US)
32AQI (US)
21AQI (US)
30AQI (US)
25AQI (US)
39AQI (US)
37AQI (US)
36AQI (US)
24AQI (US)
24AQI (US)
36AQI (US)
39AQI (US)
22AQI (US)
26AQI (US)
32AQI (US)
No. of days
202628AQI (US)
Highest AQI (US) recorded in
February32AQI (US)
Lowest AQI (US) recorded in
January26AQI (US)
202535AQI (US)
Highest AQI (US) recorded in
October46AQI (US)
Lowest AQI (US) recorded in
May24AQI (US)
202456AQI (US)
Highest AQI (US) recorded in
June70AQI (US)
Lowest AQI (US) recorded in
November28AQI (US)
202366AQI (US)
Highest AQI (US) recorded in
July70AQI (US)
Lowest AQI (US) recorded in
December40AQI (US)
202270AQI (US)
Highest AQI (US) recorded in
April73AQI (US)
Lowest AQI (US) recorded in
November68AQI (US)
202154AQI (US)
Highest AQI (US) recorded in
June71AQI (US)
Lowest AQI (US) recorded in
February22AQI (US)
202040AQI (US)
Highest AQI (US) recorded in
August57AQI (US)
Lowest AQI (US) recorded in
December25AQI (US)
Most & Least Polluted Years Over the Last 7 Years
Welby's annual 2026 AQI (US) (28) shows an average percentage change of -43.8% (improved AQI (US)) compared to previous years: 2020 (40), 2021 (54), 2022 (70), 2023 (66), 2024 (56), 2025 (35).