Worst Cities for Pollen — October 18, 2026
Pollen Atlas data shows seven cities tied at the top of the October 18, 2026 rankings — Baltimore, Dallas, Fort Worth, Fresno, Philadelphia, Sacramento and Washington, DC — each at a Total Pollen Index of 18 (Low), with ragweed as the dominant allergen in all seven.
Pollen Atlas data captured Sunday, October 18, 2026 — rankings generation 12:54 UTC (08:54 EDT) · 60 cities tracked · Methodology v1-2026-10.
Top 10 worst cities
| Rank | City | Total Pollen Index (0–100) | Band | Dominant allergen |
|---|---|---|---|---|
| 1 | Baltimore, MD | 18 | Low | Ragweed |
| 1 | Dallas, TX | 18 | Low | Ragweed |
| 1 | Fort Worth, TX | 18 | Low | Ragweed |
| 1 | Fresno, CA | 18 | Low | Ragweed |
| 1 | Philadelphia, PA | 18 | Low | Ragweed |
| 1 | Sacramento, CA | 18 | Low | Ragweed |
| 1 | Washington, DC | 18 | Low | Ragweed |
| 8 | Austin, TX | 14 | Low | Ragweed |
| 8 | Houston, TX | 14 | Low | Ragweed |
| 8 | Jacksonville, FL | 14 | Low | Ragweed |
| 8 | New Orleans, LA | 14 | Low | Ragweed |
| 8 | San Antonio, TX | 14 | Low | Ragweed |
7 cities share rank 1 (the top rank) at a Total Pollen Index of 18, and 5 cities share rank 8 at a Total Pollen Index of 14. Tied cities are listed alphabetically in this seed record.
Per-allergen leaders, October 18, 2026
- Tree: Pollen Atlas data shows 7 cities tied for the highest tree pollen reading on October 18, 2026, each at 1.1 (Low): Austin, TX, Houston, TX, Jacksonville, FL, New Orleans, LA, San Antonio, TX, Boca Raton, FL, Miami, FL.
- Grass: Pollen Atlas data shows 42 cities tied for the highest grass pollen reading on October 18, 2026, each at 0.8 (Low): Baltimore, MD, Dallas, TX, Fort Worth, TX, Fresno, CA, Philadelphia, PA, Sacramento, CA, Washington, DC, Austin, TX, Houston, TX, Jacksonville, FL, New Orleans, LA, San Antonio, TX, Albuquerque, NM, Atlanta, GA, Bakersfield, CA, Charlotte, NC, El Paso, TX, Greenville, SC, Las Vegas, NV, Long Beach, CA, Los Angeles, CA, Mesa, AZ, New York, NY, Oklahoma City, OK, Phoenix, AZ, Raleigh, NC, San Diego, CA, Santa Clarita, CA, Thousand Oaks, CA, Tucson, AZ, Tulsa, OK, Virginia Beach, VA, Boca Raton, FL, Miami, FL, Memphis, TN, Nashville, TN, Oakland, CA, Provo, UT, Salt Lake City, UT, San Francisco, CA, San Jose, CA, Wichita, KS.
- Weed (ragweed): Pollen Atlas data shows 31 cities tied for the highest weed (ragweed) reading on October 18, 2026, each at 3.7 (Moderate): Baltimore, MD, Dallas, TX, Fort Worth, TX, Fresno, CA, Philadelphia, PA, Sacramento, CA, Washington, DC, Austin, TX, Houston, TX, Jacksonville, FL, New Orleans, LA, San Antonio, TX, Albuquerque, NM, Atlanta, GA, Bakersfield, CA, Charlotte, NC, El Paso, TX, Greenville, SC, Las Vegas, NV, Long Beach, CA, Los Angeles, CA, Mesa, AZ, New York, NY, Oklahoma City, OK, Phoenix, AZ, Raleigh, NC, San Diego, CA, Santa Clarita, CA, Thousand Oaks, CA, Tucson, AZ, Virginia Beach, VA.
- Mold: Pollen Atlas data shows 9 cities tied for the highest mold reading on October 18, 2026, each at 3.7 (Moderate): Baltimore, MD, Dallas, TX, Fort Worth, TX, Fresno, CA, Philadelphia, PA, Sacramento, CA, Washington, DC, Tulsa, OK, Louisville, KY.
Full rankings — all 60 cities
| Rank | City | Total (/100) | Tree | Grass | Weed (ragweed) | Mold | Dominant allergen | 5-day outlook at capture |
|---|---|---|---|---|---|---|---|---|
| 1 | Baltimore, MD | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 12 · 12 · 17 · 18 |
| 1 | Dallas, TX | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 17 · 23 · 28 · 30 |
| 1 | Fort Worth, TX | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 23 · 27 · 30 · 32 |
| 1 | Fresno, CA | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 23 · 24 · 21 · 18 |
| 1 | Philadelphia, PA | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 23 · 23 · 24 · 26 |
| 1 | Sacramento, CA | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 25 · 24 · 21 · 18 |
| 1 | Washington, DC | 18 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 3.7 (Moderate) | Ragweed | 18 · 10 · 11 · 16 · 18 |
| 8 | Austin, TX | 14 (Low) | 1.1 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 14 · 11 · 14 · 15 · 18 |
| 8 | Houston, TX | 14 (Low) | 1.1 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 14 · 18 · 22 · 24 · 27 |
| 8 | Jacksonville, FL | 14 (Low) | 1.1 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 14 · 14 · 15 · 17 · 21 |
| 8 | New Orleans, LA | 14 (Low) | 1.1 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 14 · 13 · 21 · 23 · 25 |
| 8 | San Antonio, TX | 14 (Low) | 1.1 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 14 · 11 · 14 · 16 · 18 |
| 13 | Albuquerque, NM | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 11 · 11 · 13 · 14 |
| 13 | Atlanta, GA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 19 · 23 · 23 · 24 |
| 13 | Bakersfield, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 16 · 15 · 13 · 12 |
| 13 | Charlotte, NC | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 23 · 23 · 25 · 26 |
| 13 | El Paso, TX | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 22 · 22 · 21 · 19 |
| 13 | Greenville, SC | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 23 · 21 · 23 · 23 |
| 13 | Las Vegas, NV | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 15 · 13 · 13 · 11 |
| 13 | Long Beach, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 13 · 14 · 13 |
| 13 | Los Angeles, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 16 · 16 · 14 · 11 |
| 13 | Mesa, AZ | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 12 · 10 · 13 |
| 13 | New York, NY | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 18 · 17 · 18 · 18 |
| 13 | Oklahoma City, OK | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 20 · 23 · 24 · 25 |
| 13 | Phoenix, AZ | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 12 · 10 · 13 |
| 13 | Raleigh, NC | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 17 · 16 · 17 · 17 |
| 13 | San Diego, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 14 · 13 · 13 |
| 13 | Santa Clarita, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 16 · 16 · 15 · 11 |
| 13 | Thousand Oaks, CA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 17 · 15 · 12 |
| 13 | Tucson, AZ | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 12 · 9 · 7 · 8 |
| 13 | Tulsa, OK | 12 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 3.7 (Moderate) | Ragweed | 12 · 33 · 34 · 36 · 38 |
| 13 | Virginia Beach, VA | 12 (Low) | 0 (Low) | 0.8 (Low) | 3.7 (Moderate) | 1.2 (Low) | Ragweed | 12 · 8 · 6 · 9 · 14 |
| 33 | Louisville, KY | 10 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 3.7 (Moderate) | Ragweed | 10 · 11 · 13 · 17 · 18 |
| 34 | Boca Raton, FL | 9 (Low) | 1.1 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 9 · 9 · 9 · 16 · 22 |
| 34 | Miami, FL | 9 (Low) | 1.1 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 9 · 4 · 7 · 16 · 22 |
| 36 | Memphis, TN | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 6 · 13 · 18 · 21 |
| 36 | Nashville, TN | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 6 · 13 · 18 · 21 |
| 36 | Oakland, CA | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 7 · 14 · 12 · 8 |
| 36 | Provo, UT | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 10 · 10 · 11 · 10 |
| 36 | Salt Lake City, UT | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 10 · 14 · 13 · 14 |
| 36 | San Francisco, CA | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 13 · 14 · 11 · 7 |
| 36 | San Jose, CA | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 10 · 9 · 8 · 6 |
| 36 | Wichita, KS | 7 (Low) | 0 (Low) | 0.8 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 7 · 3 · 12 · 15 · 16 |
| 44 | Boise, ID | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 20 · 22 · 19 · 15 |
| 44 | Boston, MA | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 3 · 3 · 4 · 7 |
| 44 | Colorado Springs, CO | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 3 · 3 · 8 · 10 |
| 44 | Denver, CO | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 4 · 4 · 8 · 11 |
| 44 | Ogden, UT | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 5 · 11 · 8 · 14 |
| 44 | Rochester, NY | 5 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | 1.2 (Low) | Ragweed | 5 · 5 · 5 · 7 · 8 |
| 50 | Chicago, IL | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 9 · 11 |
| 50 | Columbus, OH | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 9 · 13 |
| 50 | Detroit, MI | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 11 · 13 |
| 50 | Indianapolis, IN | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 9 · 12 |
| 50 | Kansas City, MO | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 11 · 13 |
| 50 | Milwaukee, WI | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 5 · 9 · 12 |
| 50 | Minneapolis, MN | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 3 · 4 · 8 |
| 50 | Omaha, NE | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 4 · 9 · 13 |
| 50 | Portland, OR | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 3 · 4 · 5 |
| 50 | Seattle, WA | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 3 · 3 · 3 · 4 |
| 50 | Spokane, WA | 3 (Low) | 0 (Low) | 0 (Low) | 0 (Low) | 1.2 (Low) | Tree | 3 · 10 · 8 · 8 · 6 |
Outlook values are the forecast made on October 18, 2026; they are not observations for those later dates. City links open that city's current page.
Methodology
How the Pollen Atlas city rankings work
Pollen Atlas ranks the U.S. cities it tracks each day by the Total Pollen Index — a composite score from 0 to 100 for a city's overall pollen level: Low (0–33), Moderate (34–66), High (67–100). Each city's page also shows the day's dominant allergen and separate readings for tree pollen, grass pollen, weed pollen (ragweed), and mold, plus plant-level detail for the species currently affecting the city, including whether each plant is in season.
Sources. Pollen index figures are AccuWeather data presented via Pollen Atlas; plant-level detail comes from the Google Pollen API — the same source lines printed on every Pollen Atlas city page.
Updates. Figures update through the day, and every city page carries the date it was last updated. A ranking is a snapshot: a city's index can move between the morning and the evening of the same day.
Limits. The Total Pollen Index is a relative guide to a city's overall pollen level, not a direct count of pollen grains and not a medical measure. Category readings (tree / grass / weed / mold) are forecast values produced at regional resolution, so nearby cities can show identical category figures on the same day. Plant "in season" flags come from the plant-detail source and can differ from the category readings.
Full daily rankings: https://www.pollenatlas.com/city-rankings
Source lines: Pollen indexes: AccuWeather data via Pollen Atlas. · Plant detail: Google Pollen API.
No snapshots were captured for October 16, 2026 – October 17, 2026; Monday, October 19, 2026.