. 2021 Jul 21;20:85. doi: 10.1186/s12940-021-00766-3

Table 1.

Descriptive statistics of pollen distribution from 2008–2015; Average annual season length and range based on all three types of pollen combined; ^a missing pollen days calculated based on days within the entire pollen season; ^b Total number of days over the entire study period in ‘low’ (L), ‘moderate’ (M), ‘moderately high’ (MH), ‘high’ (H) and ‘very high’ (VH) categories are based on daily pollen concentrations (grains/m³): (tree pollen: 90–250, 250–1500, > 1500; grass pollen: 19–50, 50–100, > 100; weed pollen: 50–100, 100–250, > 250). Table cells in grey indicate very low prevalence of the type of pollen if number of days in ‘high’ pollen category were < = 10 days during the entire study period

Location	Average (range) annual pollen season length (days)	Missing pollen (% of days) ^a	Number of Tree pollen days ^b					Number of Grass pollen days ^b					Number of Weed pollen days ^b
Location	Average (range) annual pollen season length (days)	Missing pollen (% of days) ^a	L	M	MH	H	VH	L	M	MH	H	VH	L	M	MH	H	VH
Atlanta, GA	282 (272,302)	28	1368	334	149	132	68	1809	208	34	.	.	1723	274	43	11	.
Austin, TX	312 (306,327)	30	1147	358	145	196	93	1590	301	68	10	6	1704	170	44	60	.
Baltimore, MD	209 (195,229)	6	1389	163	87	122	34	1268	308	102	74	41	1572	171	44	8	.
Chicago, IL	181 (167,206)	30	740	212	123	53	6	770	266	84	14	.	619	409	81	24	1
College Station, TX	308 (294,317)	27	1453	271	125	190	51	1634	328	94	22	17	1612	300	81	89	13
Colorado Springs, CO	233 (224,247)	9	965	449	302	152	2	1188	518	135	23	6	1143	500	139	85	3
Dayton, OH	251 (235,285)	32	1360	237	120	173	35	1482	306	104	23	10	1609	210	47	59	.
Erie, PA	173 (165,190)	38	611	128	90	135	20	684	234	42	20	4	692	219	52	21	.
Eugene, OR	279 (224,344)	35	951	400	176	84	3	995	272	99	69	177	1571	44	.	.	.
Houston, TX	320 (314,323)	34	700	207	91	135	44	741	316	95	21	6	852	162	54	80	30
Kansas City, MO	240 (224,254)	31	868	143	106	193	75	598	424	195	81	89	780	311	82	155	60
Louisville, KY	242 (228,269)	2	2200	219	174	230	16	2449	239	109	31	11	2401	244	110	84	.
Madison, WI	186 (161,217)	46	632	111	83	107	10	789	101	48	5	.	553	222	87	80	1
Minneapolis, MN	197 (179,216)	22	662	106	81	128	38	823	137	46	7	2	616	252	88	58	1
Waterbury, CT	171 (169,182)	31	613	126	84	140	42	901	93	7	3	1	883	113	9	.	.
Oklahoma City, OK	318 (269,327)	33	1007	314	192	225	60	955	392	305	124	26	1142	389	68	188	19
Omaha, NE	231 (218,250)	4	1523	214	167	164	43	1600	364	109	29	10	1349	381	143	231	8
Rochester, NY	191 (175,211)	30	729	137	167	151	2	821	198	113	40	14	846	173	54	113	.
Saint Louis, MO	261 (240,280)	30	1488	175	114	148	65	1694	178	75	27	16	1405	392	106	87	.
Salt Lake City, UT	221 (211,236)	37	874	227	69	38	2	923	235	50	1	1	754	387	63	6	.
San Antonio, TX	306 (205,328)	9	992	446	160	151	44	995	664	157	4	.	957	608	125	126	4
San Jose, CA	321 (228,333)	17	1150	790	295	136	7	2015	240	66	30	30	2184	179	17	2	.
Seattle, WA	187 (171,210)	6	658	514	231	181	19	1233	262	98	10	.	1451	141	6	4	1
Springfield, MO	229 (224,233)	31	669	133	82	107	16	502	359	101	21	23	460	413	72	62	.
Tulsa, OK	294 (252,314)	53	802	156	119	135	52	734	270	166	65	24	877	200	37	117	32
Waco, TX	330 (328,333)	30	507	353	336	571	72	1269	232	193	112	130	1364	176	89	219	88
Washington, DC	236 (212,254)	36	1191	162	120	163	25	1365	241	47	8	.	1457	195	9	.	.
York, PA	204 (192,217)	33	801	172	114	150	19	1032	125	59	33	7	975	237	30	14	.