When to plant Watermelon in Washington, United States

Watermelon details page

Growing Watermelon in Washington

Days suitable for growing Watermelon in Washington

On average Watermelon needs from 65 to 100 days to mature and produce harvest.

It could prove difficult to start growing Watermelon in Washington, when planting directly into soil, due to short growing period suitable for growing Watermelon .

In order to have a chance of getting any harvest, all available season extention methods should be utilised.

Start seeds indoors

July 20 is on average first day in Washington that has required temperatures for young Watermelon seedlings to grow, without worrying about cold damage.

Seeds can be started indoors beween June 01 and June 18, this way they will be ready just in time for transplanting on July 20.

Seedlings started after June 18 might not have enough time to mature and produce harvest.

Use a cold frame

When using a cold frame in a beggining of growing season You can protect young plants from possible temperature drops, this way growing season can start up to 2 weeks earlier.

Use an additional shading

On days, when air temperatures are expected to raise above 100°F, which is in top of tolerable range for Watermelon , consider using additional shading to prevent heat shock.

Total frost free days	189
Last frost expected date	April 20
First frost expected date	October 26
Dates with ideal conditions
Dates with suitable conditions	June 26 to June 29 (4 days) July 01 July 06 to July 07 (2 days) July 10 July 12 to July 13 (2 days) July 15 to July 17 (3 days) July 20 to August 22 (34 days) August 25 to August 26 (2 days) August 29 to August 30 (2 days) September 03
Total days ideal for growing Watermelon in Washington	0
Total days suitable for growing Watermelon in Washington	52
Days needed for Watermelon to mature and produce harvest	65 - 100
Seed can be planted directly into soil	no
Seed has to be started indoors	yes

Notable temperature facts for growing Watermelon in Washington

Table with days suitable to grow vegetables in Washington

Tolerable temperature range for Watermelon : 55°F to 100°F

	Week	Average temperature	Possible min and max temperature	Suitable for Watermelon
1	January 01 - January 03	31°F to 40°F	10°F to 49°F
2	January 04 - January 10	33°F to 42°F	24°F to 48°F
3	January 11 - January 17	33°F to 43°F	22°F to 50°F
4	January 18 - January 24	33°F to 42°F	26°F to 47°F
5	January 25 - January 31	31°F to 43°F	20°F to 50°F
6	February 01 - February 07	32°F to 42°F	17°F to 51°F
7	February 08 - February 14	29°F to 40°F	14°F to 51°F
8	February 15 - February 21	30°F to 41°F	20°F to 49°F
9	February 22 - February 28	28°F to 40°F	17°F to 53°F
10	March 01 - March 07	31°F to 45°F	15°F to 53°F
11	March 08 - March 14	30°F to 45°F	20°F to 54°F
12	March 15 - March 21	33°F to 51°F	24°F to 63°F
13	March 22 - March 28	36°F to 51°F	29°F to 60°F
14	March 29 - April 04	36°F to 51°F	29°F to 61°F
15	April 05 - April 11	37°F to 52°F	29°F to 64°F
16	April 12 - April 18	36°F to 54°F	29°F to 71°F
17	April 19 - April 25	40°F to 57°F	32°F to 69°F
18	April 26 - May 02	42°F to 60°F	35°F to 73°F
19	May 03 - May 09	43°F to 61°F	36°F to 72°F
20	May 10 - May 16	47°F to 66°F	36°F to 80°F
21	May 17 - May 23	46°F to 63°F	38°F to 77°F
22	May 24 - May 30	48°F to 65°F	42°F to 77°F
23	May 31 - June 06	50°F to 69°F	44°F to 82°F
24	June 07 - June 13	50°F to 67°F	43°F to 83°F
25	June 14 - June 20	50°F to 66°F	44°F to 78°F
26	June 21 - June 27	54°F to 75°F	47°F to 97°F
27	June 28 - July 04	55°F to 75°F	49°F to 101°F
28	July 05 - July 11	55°F to 74°F	50°F to 85°F
29	July 12 - July 18	56°F to 76°F	49°F to 85°F	TRUE
30	July 19 - July 25	56°F to 78°F	50°F to 85°F	TRUE
31	July 26 - August 01	59°F to 83°F	51°F to 91°F	TRUE
32	August 02 - August 08	58°F to 79°F	52°F to 87°F	TRUE
33	August 09 - August 15	58°F to 79°F	50°F to 91°F	TRUE
34	August 16 - August 22	59°F to 79°F	52°F to 92°F	TRUE
35	August 23 - August 29	55°F to 76°F	49°F to 85°F
36	August 30 - September 05	55°F to 75°F	46°F to 87°F
37	September 06 - September 12	55°F to 75°F	50°F to 84°F
38	September 13 - September 19	52°F to 69°F	44°F to 79°F
39	September 20 - September 26	51°F to 67°F	45°F to 78°F
40	September 27 - October 03	47°F to 63°F	37°F to 77°F
41	October 04 - October 10	47°F to 64°F	33°F to 75°F
42	October 11 - October 17	45°F to 59°F	35°F to 74°F
43	October 18 - October 24	44°F to 56°F	36°F to 68°F
44	October 25 - October 31	37°F to 50°F	28°F to 58°F
45	November 01 - November 07	39°F to 50°F	31°F to 58°F
46	November 08 - November 14	35°F to 46°F	27°F to 56°F
47	November 15 - November 21	35°F to 46°F	26°F to 55°F
48	November 22 - November 28	34°F to 44°F	27°F to 53°F
49	November 29 - December 05	32°F to 42°F	18°F to 54°F
50	December 06 - December 12	34°F to 42°F	27°F to 49°F
51	December 13 - December 19	31°F to 40°F	22°F to 46°F
52	December 20 - December 26	31°F to 39°F	8°F to 49°F
53	December 27 - December 31	31°F to 39°F	14°F to 49°F

Days with suitable temperature for growing Watermelon in Washington

Watermelon details page

For more precise weather statisctics and planting information, please select a County in Washington.

All data is provided “as is” without warranty or any representation of accuracy, timeliness or completeness.

Average daily temperatures were calculated using

Weather data provided by OpenWeather