Silver Sands State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Silver Sands State Park clear sky chart from 2005-11-06 to 2026-02-01.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	17% 7% 2 6% 4 4 4 4 5% 7% 40%	127352
	Night	18% 8% 2 6% 4 3 4 3 5% 6% 42%	124684
Transparency	Day	40% 6% 13% 23% 16% 3	130881
	Night	42% 5% 11% 22% 16% 3	129230
Seeing	Day	17% 6% 25% 30% 17% 4	16533
	Night	20% 8% 29% 29% 12% 2	25704

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	13% 6% 2 5% 4 4 4 4 5% 6% 47%	3677
	11th to 20th	Day	14% 8% 3 5% 4 4 3 4 5% 5% 44%	3650
	21st to end	Day	18% 6% 3 7% 4 4 4 3 5% 5% 40%	4216
February	1st to 10th	Day	17% 7% 2 5% 5% 5% 5% 3 5% 7% 39%	1865
	11th to 20th	Day	15% 6% 2 6% 4 3 4 5% 6% 7% 43%	1948
	21st to end	Day	21% 8% 2 5% 4 4 3 4 5% 6% 39%	1650
March	1st to 10th	Day	23% 7% 2 5% 3 3 3 3 4 5% 41%	4476
	11th to 20th	Day	13% 9% 2 5% 3 3 4 4 5% 8% 44%	4682
	21st to end	Day	19% 7% 2 6% 4 4 4 4 5% 6% 38%	5970
April	1st to 10th	Day	20% 8% 2 4 4 4 4 4 6% 6% 37%	2400
	11th to 20th	Day	19% 6% 2 6% 4 4 3 3 5% 7% 42%	2374
	21st to end	Day	20% 6% 2 6% 4 3 4 3 5% 6% 41%	2492
May	1st to 10th	Day	30% 7% 2 5% 3 3 4 3 5% 8% 29%	5886
	11th to 20th	Day	22% 9% 2 7% 4 3 4 3 5% 7% 36%	6130
	21st to end	Day	20% 6% 2 6% 4 4 4 4 6% 7% 36%	6949
June	1st to 10th	Day	18% 6% 1 5% 4 4 5% 4 7% 8% 37%	2800
	11th to 20th	Day	16% 6% 2 5% 4 4 5% 4 6% 9% 39%	2800
	21st to end	Day	12% 7% 2 6% 4 4 5% 4 6% 9% 42%	2800
July	1st to 10th	Day	13% 7% 3 7% 5% 4 5% 4 7% 11% 35%	6360
	11th to 20th	Day	12% 7% 3 7% 4 5% 5% 4 7% 11% 36%	6360
	21st to end	Day	14% 6% 2 7% 4 4 5% 4 5% 7% 42%	6926
August	1st to 10th	Day	18% 6% 3 7% 4 4 4 4 7% 8% 35%	4377
	11th to 20th	Day	12% 6% 2 6% 4 3 4 3 6% 9% 45%	3850
	21st to end	Day	7% 5% 2 5% 4 4 5% 4 7% 9% 47%	4312
September	1st to 10th	Day	14% 5% 2 5% 4 4 4 4 5% 6% 47%	2400
	11th to 20th	Day	12% 5% 2 4 3 3 4 4 4 7% 53%	2269
	21st to end	Day	19% 6% 2 7% 4 4 4 3 5% 6% 40%	2200
October	1st to 10th	Day	20% 6% 2 5% 3 3 4 2 5% 5% 44%	2160
	11th to 20th	Day	15% 5% 2 5% 3 3 3 3 6% 8% 47%	1998
	21st to end	Day	19% 5% 2 4 4 4 4 3 6% 7% 42%	1980
November	1st to 10th	Day	13% 6% 2 6% 4 3 3 2 5% 6% 49%	1851
	11th to 20th	Day	17% 6% 1 4 3 4 3 3 5% 6% 49%	1890
	21st to end	Day	17% 7% 2 5% 3 3 3 4 5% 7% 44%	1860
December	1st to 10th	Day	16% 6% 2 5% 3 4 4 3 5% 7% 45%	2680
	11th to 20th	Day	23% 6% 2 4 3 2 2 2 4 6% 46%	3066
	21st to end	Day	19% 10% 3 6% 3 3 3 2 4 6% 39%	4048
January	1st to 10th	Night	14% 6% 2 5% 3 3 3 3 5% 7% 49%	6489
	11th to 20th	Night	15% 8% 3 7% 4 3 3 3 4 5% 46%	6455
	21st to end	Night	18% 9% 3 6% 4 4 4 3 4 5% 39%	6980
February	1st to 10th	Night	17% 9% 3 6% 4 3 4 4 5% 5% 41%	2535
	11th to 20th	Night	18% 8% 3 5% 4 3 3 3 5% 7% 41%	2338
	21st to end	Night	20% 7% 3 5% 4 4 3 3 4 5% 42%	1980
March	1st to 10th	Night	21% 9% 2 5% 3 3 3 3 4 5% 41%	5364
	11th to 20th	Night	17% 10% 2 5% 4 4 3 3 4 5% 42%	5273
	21st to end	Night	21% 9% 3 6% 4 4 3 3 4 5% 39%	4962
April	1st to 10th	Night	20% 6% 3 8% 4 4 4 4 5% 6% 38%	2000
	11th to 20th	Night	21% 6% 2 6% 4 3 4 3 5% 6% 42%	1975
	21st to end	Night	20% 7% 2 6% 4 3 4 3 4 5% 43%	1906
May	1st to 10th	Night	28% 11% 3 6% 4 3 4 3 4 6% 27%	4054
	11th to 20th	Night	24% 9% 2 5% 4 3 4 4 5% 7% 33%	3805
	21st to end	Night	24% 8% 3 6% 4 4 4 3 4 6% 34%	3926
June	1st to 10th	Night	19% 6% 2 5% 4 5% 4 4 5% 6% 40%	1600
	11th to 20th	Night	17% 7% 2 6% 3 4 4 3 6% 9% 40%	1600
	21st to end	Night	13% 6% 2 6% 4 5% 4 3 5% 9% 43%	1600
July	1st to 10th	Night	15% 8% 2 7% 5% 4 4 4 6% 8% 36%	3600
	11th to 20th	Night	19% 9% 3 6% 4 3 5% 4 6% 9% 32%	3600
	21st to end	Night	15% 7% 2 6% 4 4 4 4 6% 6% 42%	3926
August	1st to 10th	Night	23% 6% 3 7% 4 4 5% 5% 7% 6% 30%	2735
	11th to 20th	Night	14% 7% 2 6% 4 5% 5% 4 6% 7% 40%	3197
	21st to end	Night	9% 4 2 4 4 3 4 3 5% 8% 55%	3586
September	1st to 10th	Night	14% 6% 3 5% 4 5% 4 4 5% 7% 44%	2000
	11th to 20th	Night	14% 5% 1 4 4 2 4 2 4 6% 53%	2130
	21st to end	Night	19% 8% 2 5% 4 4 4 3 4 5% 43%	2200
October	1st to 10th	Night	19% 7% 3 5% 4 4 4 2 4 7% 41%	2237
	11th to 20th	Night	16% 5% 2 6% 3 3 3 3 4 6% 49%	2400
	21st to end	Night	21% 7% 2 5% 3 3 3 3 5% 6% 42%	2860
November	1st to 10th	Night	12% 5% 2 6% 4 3 3 3 5% 6% 49%	2667
	11th to 20th	Night	19% 7% 2 4 3 3 3 3 4 6% 48%	2730
	21st to end	Night	15% 5% 2 5% 4 4 3 3 4 7% 46%	2756
December	1st to 10th	Night	17% 7% 2 5% 3 3 4 3 4 5% 49%	4720
	11th to 20th	Night	26% 7% 2 4 3 3 3 3 3 4 43%	5348
	21st to end	Night	19% 9% 3 6% 3 3 3 3 4 5% 42%	7150

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	34% 3 9% 31% 19% 3	3678
	11th to 20th	Day	39% 5% 11% 22% 16% 7%	3680
	21st to end	Day	44% 5% 11% 23% 15% 1	4216
February	1st to 10th	Day	44% 5% 13% 22% 15% 2	1865
	11th to 20th	Day	40% 5% 10% 25% 17% 3	1957
	21st to end	Day	44% 5% 10% 21% 16% 3	1650
March	1st to 10th	Day	43% 3 13% 18% 14% 10%	4479
	11th to 20th	Day	36% 7% 13% 28% 14% 2	4682
	21st to end	Day	43% 5% 9% 15% 22% 6%	5970
April	1st to 10th	Day	43% 7% 10% 20% 16% 4	2400
	11th to 20th	Day	41% 6% 11% 21% 19% 3	2374
	21st to end	Day	41% 6% 10% 22% 17% 4	2492
May	1st to 10th	Day	51% 7% 16% 15% 9% 1	5897
	11th to 20th	Day	47% 6% 13% 19% 13% 2	6134
	21st to end	Day	43% 7% 12% 24% 13% 1	6949
June	1st to 10th	Day	40% 8% 12% 24% 14% 1	2800
	11th to 20th	Day	38% 8% 14% 25% 13% 1	2800
	21st to end	Day	35% 9% 16% 24% 15% 1	2800
July	1st to 10th	Day	41% 11% 13% 20% 14% 1	6290
	11th to 20th	Day	39% 8% 19% 23% 10% 1	6285
	21st to end	Day	39% 6% 11% 23% 20% 1	6728
August	1st to 10th	Day	44% 7% 16% 23% 9% 1	4363
	11th to 20th	Day	34% 6% 15% 32% 12% 1	3886
	21st to end	Day	29% 8% 13% 30% 19% 2	4312
September	1st to 10th	Day	36% 7% 13% 23% 20% 2	2400
	11th to 20th	Day	30% 6% 11% 25% 26% 2	2269
	21st to end	Day	43% 6% 10% 20% 18% 3	2200
October	1st to 10th	Day	33% 6% 10% 23% 23% 5%	3524
	11th to 20th	Day	27% 3 11% 25% 30% 4	3226
	21st to end	Day	30% 4 14% 26% 22% 3	3180
November	1st to 10th	Day	36% 4 14% 21% 22% 2	1851
	11th to 20th	Day	37% 4 10% 22% 23% 3	1890
	21st to end	Day	40% 3 14% 28% 12% 2	1860
December	1st to 10th	Day	40% 3 16% 28% 13% 1	2680
	11th to 20th	Day	41% 2 15% 20% 19% 3	3066
	21st to end	Day	47% 5% 9% 21% 16% 3	4048
January	1st to 10th	Night	36% 3 9% 27% 22% 3	6489
	11th to 20th	Night	41% 4 13% 21% 16% 6%	6500
	21st to end	Night	47% 3 10% 20% 16% 4	6980
February	1st to 10th	Night	45% 4 12% 23% 13% 2	2535
	11th to 20th	Night	43% 4 9% 21% 18% 4	2340
	21st to end	Night	45% 4 8% 23% 16% 4	1980
March	1st to 10th	Night	45% 4 10% 19% 14% 8%	5374
	11th to 20th	Night	44% 5% 14% 22% 12% 4	5274
	21st to end	Night	48% 4 6% 12% 24% 6%	4962
April	1st to 10th	Night	47% 4 10% 19% 16% 4	2000
	11th to 20th	Night	44% 4 10% 19% 21% 1	1975
	21st to end	Night	43% 5% 9% 20% 18% 4	1906
May	1st to 10th	Night	57% 6% 13% 13% 9% 2	4060
	11th to 20th	Night	51% 6% 13% 14% 12% 3	3806
	21st to end	Night	51% 6% 12% 21% 10% 1	3927
June	1st to 10th	Night	44% 6% 10% 20% 18% 2	1600
	11th to 20th	Night	40% 7% 14% 27% 12% 1	1600
	21st to end	Night	38% 7% 13% 26% 14% 1	1600
July	1st to 10th	Night	45% 8% 13% 22% 11% 1	3560
	11th to 20th	Night	47% 7% 16% 20% 10%	3552
	21st to end	Night	40% 6% 14% 24% 16% 1	3809
August	1st to 10th	Night	50% 7% 15% 17% 10% 1	2725
	11th to 20th	Night	41% 7% 13% 29% 9% 1	3227
	21st to end	Night	28% 6% 12% 33% 20% 1	3586
September	1st to 10th	Night	39% 6% 10% 26% 18% 2	2000
	11th to 20th	Night	34% 4 10% 25% 24% 3	2130
	21st to end	Night	43% 5% 9% 21% 19% 3	2200
October	1st to 10th	Night	39% 5% 11% 23% 19% 3	3653
	11th to 20th	Night	26% 3 10% 26% 31% 4	3899
	21st to end	Night	32% 4 13% 27% 22% 2	4610
November	1st to 10th	Night	36% 4 12% 24% 20% 4	2667
	11th to 20th	Night	39% 3 9% 24% 20% 5%	2730
	21st to end	Night	38% 5% 12% 30% 13% 2	2756
December	1st to 10th	Night	39% 3 12% 31% 13% 2	4720
	11th to 20th	Night	47% 3 10% 20% 17% 3	5348
	21st to end	Night	45% 4 10% 20% 17% 4	7150

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	18% 13% 35% 25% 8% 1	220
	11th to 20th	Day	15% 15% 42% 22% 4 1	220
	21st to end	Day	19% 6% 42% 24% 7% 2	283
February	1st to 10th	Day	22% 9% 38% 25% 7%	365
	11th to 20th	Day	19% 11% 43% 24% 3	496
	21st to end	Day	21% 12% 35% 26% 5%	414
March	1st to 10th	Day	17% 10% 39% 29% 5%	500
	11th to 20th	Day	16% 6% 42% 26% 8% 1	500
	21st to end	Day	21% 7% 39% 25% 7% 1	550
April	1st to 10th	Day	23% 8% 33% 24% 9% 1	500
	11th to 20th	Day	18% 9% 33% 29% 10% 1	492
	21st to end	Day	23% 7% 24% 33% 10% 2	500
May	1st to 10th	Day	28% 5% 26% 30% 10% 2	503
	11th to 20th	Day	19% 4 25% 34% 16% 1	527
	21st to end	Day	18% 3 16% 34% 23% 6%	573
June	1st to 10th	Day	18% 2 18% 34% 22% 6%	530
	11th to 20th	Day	15% 4 17% 35% 24% 5%	530
	21st to end	Day	12% 4 16% 35% 26% 8%	530
July	1st to 10th	Day	14% 3 11% 31% 32% 10%	525
	11th to 20th	Day	11% 4 8% 31% 36% 10%	524
	21st to end	Day	12% 3 13% 37% 30% 5%	576
August	1st to 10th	Day	11% 3 9% 38% 29% 10%	526
	11th to 20th	Day	13% 2 8% 34% 31% 11%	519
	21st to end	Day	11% 3 13% 37% 28% 9%	583
September	1st to 10th	Day	17% 2 17% 28% 25% 10%	530
	11th to 20th	Day	13% 3 18% 27% 28% 12%	530
	21st to end	Day	20% 5% 20% 29% 22% 4	530
October	1st to 10th	Day	22% 5% 17% 26% 20% 9%	530
	11th to 20th	Day	16% 7% 28% 29% 17% 3	528
	21st to end	Day	23% 8% 27% 27% 13% 2	462
November	1st to 10th	Day	13% 8% 26% 34% 16% 3	425
	11th to 20th	Day	17% 10% 39% 24% 10%	430
	21st to end	Day	20% 12% 33% 26% 10% 1	400
December	1st to 10th	Day	18% 10% 36% 27% 9% 1	220
	11th to 20th	Day	25% 10% 35% 24% 6%	220
	21st to end	Day	22% 7% 36% 24% 9% 2	242
January	1st to 10th	Night	19% 14% 39% 22% 5%	840
	11th to 20th	Night	24% 13% 37% 23% 4	840
	21st to end	Night	19% 13% 40% 25% 2	924
February	1st to 10th	Night	21% 11% 39% 27% 2	801
	11th to 20th	Night	23% 10% 43% 22% 2	783
	21st to end	Night	24% 10% 39% 22% 5%	660
March	1st to 10th	Night	21% 10% 38% 25% 7%	800
	11th to 20th	Night	20% 8% 36% 28% 7% 1	800
	21st to end	Night	21% 7% 37% 27% 7% 1	880
April	1st to 10th	Night	22% 7% 33% 31% 6% 1	800
	11th to 20th	Night	23% 5% 32% 30% 10%	791
	21st to end	Night	21% 5% 31% 33% 9% 1	706
May	1st to 10th	Night	26% 6% 26% 28% 13% 1	600
	11th to 20th	Night	22% 5% 29% 33% 11% 1	494
	21st to end	Night	21% 2 15% 36% 23% 2	433
June	1st to 10th	Night	20% 4 20% 34% 21% 2	400
	11th to 20th	Night	19% 3 13% 44% 21% 1	400
	21st to end	Night	12% 2 15% 47% 23% 2	400
July	1st to 10th	Night	13% 3 15% 36% 30% 3	390
	11th to 20th	Night	13% 3 11% 41% 29% 3	388
	21st to end	Night	14% 2 14% 44% 24% 2	438
August	1st to 10th	Night	12% 2 14% 40% 30% 2	482
	11th to 20th	Night	14% 3 12% 37% 29% 6%	790
	21st to end	Night	13% 3 15% 35% 29% 5%	880
September	1st to 10th	Night	16% 2 22% 33% 23% 5%	800
	11th to 20th	Night	16% 4 17% 34% 22% 7%	800
	21st to end	Night	20% 4 21% 31% 20% 3	800
October	1st to 10th	Night	22% 6% 26% 24% 17% 5%	800
	11th to 20th	Night	18% 9% 29% 32% 11% 1	800
	21st to end	Night	24% 9% 33% 25% 9% 1	880
November	1st to 10th	Night	15% 9% 32% 29% 12% 2	820
	11th to 20th	Night	22% 12% 36% 23% 8%	840
	21st to end	Night	17% 14% 34% 27% 7% 1	840
December	1st to 10th	Night	24% 12% 35% 23% 6% 1	840
	11th to 20th	Night	23% 14% 34% 25% 3	840
	21st to end	Night	23% 13% 37% 23% 4	924

Page generated at 2026-01-29 01:21:44. Version ac07

Copyright © 2026 Attilla Danko.