Weather in Delaware

Calculated from weather data of New Castle Airport (KILG) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	43.0	42.0	50.0	40.0	42.0	47.0
February	48.0	48.0	50.0	50.0	40.0	49.0
March	54.0	57.0	55.0	57.0	57.0	59.0
April	65.0	64.0	69.0	63.0	65.0	60.0
May	73.0		74.0	75.0	73.0	69.0
June	82.0		82.0	82.0	83.0	82.0
July	87.0		88.0	88.0	86.0	89.0
August	85.0		85.0	88.0	86.0	84.0
September	79.0		78.0	79.0	79.0	76.0
October	69.0		69.0	65.0	71.0	67.0
November	56.0		54.0	60.0	55.0	61.0
December	47.0		49.0	47.0	52.0	46.0
Average	64.0	53.0	67.0	67.0	66.0	66.0

Average highest temperature per day

The maximum temperature is typically observed some hours after noon.

Minimum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	30.0	30	36	25	29	33
February	32.0	31	32	30	29	33
March	36.0	39	37	38	37	41
April	47.0	47	50	45	46	44
May	55.0		52	57	53	52
June	64.0		61	64	64	64
July	70.0		72	71	69	69
August	69.0		69	70	70	67
September	62.0		61	61	62	60
October	52.0		50	47	55	51
November	38.0		35	42	36	42
December	33.0		35	33	37	31
Average	47.0	37.0	50.0	49.0	49.0	49.0

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Cold and hot days

Number of days	2024	2023	2022	2021	2020
86 °F or warmer	0	42	49	54	42
77 °F or warmer	4	125	122	121	104
68 °F or warmer	14	173	184	183	168
32 °F or colder	38	45	70	65	51

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	12.0	21	12	15	6	5
February	13.2	13	7	16	18	16
March	11.7	19	9	11	10	11
April	7.6	12	10	8	4	8
May	8.9		4	12	6	5
June	5.8		10	4	6	2
July	4.7		6	6	3	4
August	5.0		3	1	6	9
September	6.1		13	8	5	3
October	8.6		6	11	9	10
November	7.1		6	13	4	8
December	11.6		12	25	4	9
Average	9.0	16.1	8.0	9.8	6.6	7.1

Precipitation during daylight period

Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.

Wind speed (miles per hour)

Month	Average	2024	2023	2022	2021	2020
January	10.5	10	10	10	11	10
February	10.0	9	10	11	10	9
March	11.9	11	12	12	11	10
April	11.4	11	11	12	11	13
May	9.5		8	10	9	11
June	8.9		9	9	9	9
July	7.8		8	8	8	8
August	7.9		9	8	8	8
September	8.5		9	9	10	8
October	9.1		8	9	10	8
November	10.1		9	10	10	10
December	9.3		8	10	8	11
Average	9.6	10.3	9.2	9.8	9.4	9.5

Average wind speed

Excluding wind gusts. Only observations between sunrise and sunset are taken into account.

Prevailing wind direction

Month	2024	2023	2022	2021	2020
January	NW	NW	NW	NW	NW
February	NW	W	W	NW	W
March	NW	NW	W	W	W
April	SW	SW	NW	W	NW
May		W	E	NW	NW
June		NW	SW	S	W
July		SW	SW	W	SW
August		W	SW	S	SW
September		N	NW	W	NE
October		NW	N	NW	NW
November		NW	W	NW	W
December		NW	NW	W	W

Prevailing wind direction

Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.

Delaware weather Q&A

What is the warmest month in Delaware?

The warmest month is July with an average temperature of 87 °F over the past years.

What is the coldest month in Delaware?

The coldest month is January with an average daytime temperature of 43 °F in the past few years.

Which month is the wettest in Delaware?

Chance of precipitation is the highest in February with a probability of around 13.3 %.

Which month is the driest in Delaware?

The least rainfall and snow can be expected in July. The probability is about 4.7 %.