During my time taking classes as part of Penn State University’s Undergraduate Certificate in Weather Forecasting, we were taught that understanding the climatology of the location you are interested in is an important prerequisite for making accurate forecasts. This post continues on this theme, adding a climatology for August.

Other Month’s Climatologies

January
February
March
April
May
June
July
September
October
November
December

Station Basic Information

City Name / Station ID: New York, NY (LaGuardia Airport – KLGA)

Local Geography and Topography

Station Elevation: 10 feet above sea level.

Station Location: LaGuardia Airport (KLGA) is situated on the north shore of Queens along the East River, approximately 6 miles east-northeast of Midtown Manhattan.

Important Topographical Features: New York City is located in the extreme southeastern corner of New York State, bordering suburban New Jersey and Connecticut. These suburban regions combined with those in Long Island comprise the Greater New York City Metropolitan Area, which is the most populous urban agglomeration in the United States and one of the populous urbanized areas in the world with an estimated population of 18 million. New York City itself sprawls across the coastal plain around the Hudson River estuary. The terminal moraine formed by glaciers of the last Ice Age result in a ridge of higher terrain that cuts a swath from southwest to northeast across the boroughs from northern Staten Island, northern Brooklyn, southwestern through central and northeastern Queens. Otherwise, the city itself is low lying. This ridge varies in height between 200-400 feet, rising sharply from south to north, but tapering more gently north. North and west of the city (about 30-50 miles away), lie significant elevations of the Catskills (north), Poconos (west), Taconics that are part of the broader Appalachian Mountain Range. The elevations of the lower foothills can range from 1000-1500 feet. Some of the elevations in the Poconos and Catskills, west and north of KLGA respectively, peak between 2000-3000 feet. The open expanse of the Atlantic Ocean lies south of KLGA and New York City. Long Island Sound also lies east-northeast. The vast urbanized area of the NYC metropolitan region has significant effects on local microclimates via differential heating (urban heat island effect). KLGA is in a low-lying area sensitive to UHI effects and marine influences.

Per the Local Climatological Data from the National Weather Service:

On winter mornings, ocean temperatures which are warm relative to the land reinforce the effect of the city heat island and low temperatures are often 10-20 degrees lower in the inland suburbs than in the central city. The relatively warm water temperatures also delay the advent of winter snows. Conversely, the lag in warming of water temperatures keeps spring temperatures relatively cool. One year-round measure of the ocean influence is the small average daily variation in temperature.

National Weather Service – NYC Office

Wind Patterns

Below is a wind rose – you can read more about how to interpret this chart here.

Frequency (percentage) of the single most common wind direction: Due south (12.25%).

Directions that are most and least common: Most common wind directions include due southwest (10%), due northeast (9.75%), and south-southwest (8.75%). Least common wind directions are east-southeast (1%), due southeast (2.5%), and due east (2%).

Direction(s) most likely to produce the fastest winds: Winds of 16.5-21.4 knots are most frequently found coming from due northeast, and due south. It appears that due northeast also has some probability of exceeding 21.4 knots.

Direction(s) least likely to produce the fastest winds: As is the case with several other months, the least common wind directions of due east, east-southeast, and due southeast also rarely seen winds in excess of 16.4 knots.

Impacts of wind direction on local weather: August winds continue to exhibit a distinctive summer pattern, and share many of the characteristics of the wind profiles for June and July. Southerly and southwesterly winds are a touch less common in August versus July, while northwesterly winds increase in frequency slightly. Like in July, heat waves can accompany the clockwise return flow from the southwest when subtropical Bermuda highs set up southeast of the area. A slight down tick in the frequency of southerly winds may point to a decline in sea breezes, with sea surface temperatures continuing to warm and narrowing the gap with average air temperatures. Increases in northwesterly winds could be an indication of a stronger influence from Canadian high pressure.

Maximum observed two-minute wind speed for the month: 45 (52 mph)

Temperature and Precipitation Averages/Records

Temperature units are in Fahrenheit and precipitation is in inches.

Date	Normal High	Normal Low	Record High	Record Low	Record Lowest Max	Record Highest Min	Normal Precip	Record Precip
1	85	70	100	62	69	83	0.15	2.03
2	85	70	102	59	73	86	0.15	1.31
3	85	70	100	59	70	82	0.16	2.80
4	85	70	99	62	75	80	0.15	2.78
5	85	70	100	57	69	81	0.15	2.08
6	85	70	95	57	69	81	0.15	2.34
7	85	70	99	61	65	81	0.13	1.31
8	85	70	98	59	72	81	0.14	2.54
9	85	70	104	61	71	82	0.14	2.97
10	85	70	99	57	62	81	0.14	1.91
11	85	70	99	57	68	79	0.12	2.03
12	84	70	98	56	64	82	0.13	6.40
13	84	70	100	56	67	84	0.13	4.12
14	84	69	98	59	72	81	0.14	6.60
15	84	69	97	59	67	82	0.13	0.98
16	84	69	96	58	67	79	0.14	2.48
17	84	69	94	58	70	79	0.13	3.54
18	84	69	95	59	69	81	0.13	1.18
19	84	69	94	59	71	77	0.13	2.74
20	83	69	98	58	70	77	0.14	1.31
21	83	69	97	57	62	78	0.13	1.24
22	83	68	93	55	69	78	0.13	2.34
23	83	68	92	56	70	75	0.14	1.96
24	83	68	93	55	65	77	0.13	1.40
25	83	68	96	53	67	80	0.13	2.09
26	82	68	103	53	61	80	0.12	2.58
27	82	68	99	55	70	78	0.12	4.73
28	82	67	99	54	61	81	0.11	3.62
29	82	67	100	51	66	84	0.11	2.57
30	81	67	99	54	70	81	0.11	1.89
31	81	67	100	52	68	79	0.11	1.60
Range	81-85	67-70	92-104	51-62	61-75	75-86	0.11-0.16	0.98-6.60