Golden Pond Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Golden Pond Observatory clear sky chart from 2005-11-06 to 2025-08-05.

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	13% 8% 3 7% 4 4 4 4 5% 8% 41%	125438
	Night	14% 8% 3 6% 4 4 4 3 5% 7% 42%	122768
Transparency	Day	26% 39% 7% 16% 11% 2	129082
	Night	26% 39% 6% 15% 12% 2	127197
Seeing	Day	17% 10% 24% 25% 18% 8%	16403
	Night	18% 9% 25% 29% 17% 2	26148

By Month

Percentage Cloud Cover SE (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	15% 11% 7% 10% 5% 4 4 3 4 5% 31%	3617
	11th to 20th	Day	14% 9% 2 8% 4 5% 4 2 3 5% 42%	3694
	21st to end	Day	20% 9% 4 5% 4 4 4 3 4 6% 37%	4620
February	1st to 10th	Day	19% 12% 4 5% 4 3 4 3 4 7% 36%	2000
	11th to 20th	Day	20% 10% 4 7% 4 4 3 2 5% 5% 35%	1948
	21st to end	Day	18% 11% 3 7% 5% 3 4 4 3 5% 36%	1650
March	1st to 10th	Day	16% 14% 3 8% 4 4 3 3 4 5% 38%	4480
	11th to 20th	Day	13% 9% 3 6% 3 3 3 2 4 5% 48%	4685
	21st to end	Day	12% 9% 3 7% 5% 4 4 3 4 7% 43%	5967
April	1st to 10th	Day	14% 6% 3 6% 4 5% 4 3 5% 7% 44%	2400
	11th to 20th	Day	16% 7% 3 6% 4 4 4 3 6% 6% 41%	2374
	21st to end	Day	16% 7% 3 6% 5% 4 4 3 5% 7% 41%	2400
May	1st to 10th	Day	18% 9% 4 9% 5% 5% 5% 4 6% 8% 25%	5806
	11th to 20th	Day	16% 8% 3 8% 5% 5% 5% 4 6% 8% 32%	5861
	21st to end	Day	14% 7% 3 7% 5% 5% 4 4 5% 8% 38%	6519
June	1st to 10th	Day	10% 5% 2 6% 5% 4 5% 4 7% 8% 46%	2800
	11th to 20th	Day	5% 4 2 5% 4 5% 5% 5% 8% 10% 47%	2800
	21st to end	Day	5% 4 2 5% 6% 5% 5% 5% 8% 10% 46%	2800
July	1st to 10th	Day	8% 6% 2 6% 5% 5% 5% 4 6% 10% 42%	6360
	11th to 20th	Day	6% 5% 2 6% 5% 5% 6% 5% 8% 12% 40%	6360
	21st to end	Day	8% 7% 3 8% 6% 5% 5% 5% 8% 12% 33%	6689
August	1st to 10th	Day	5% 4 1 4 4 4 6% 4 6% 9% 54%	3833
	11th to 20th	Day	8% 5% 2 6% 5% 5% 5% 4 7% 10% 42%	3729
	21st to end	Day	5% 3 2 4 3 3 4 3 6% 8% 59%	4180
September	1st to 10th	Day	11% 4 2 6% 5% 5% 5% 3 5% 8% 46%	2280
	11th to 20th	Day	11% 5% 2 5% 4 4 5% 3 4 7% 49%	2130
	21st to end	Day	11% 5% 2 5% 4 4 4 3 5% 7% 50%	2090
October	1st to 10th	Day	10% 4 2 4 3 3 4 2 4 7% 58%	2090
	11th to 20th	Day	13% 5% 2 5% 3 3 3 3 4 6% 53%	1932
	21st to end	Day	19% 8% 2 5% 4 2 2 3 3 5% 48%	1961
November	1st to 10th	Day	12% 5% 2 5% 3 3 2 3 5% 6% 53%	1762
	11th to 20th	Day	15% 8% 2 5% 3 3 3 2 4 6% 48%	1800
	21st to end	Day	18% 9% 2 6% 4 3 3 3 5% 5% 42%	1800
December	1st to 10th	Day	16% 10% 3 6% 4 3 4 3 4 5% 42%	2930
	11th to 20th	Day	17% 11% 4 7% 4 4 4 3 5% 6% 34%	3109
	21st to end	Day	19% 12% 4 9% 5% 5% 4 4 5% 7% 27%	3982
January	1st to 10th	Night	17% 13% 4 10% 4 3 4 4 5% 6% 31%	6348
	11th to 20th	Night	17% 12% 4 9% 4 4 3 2 3 3 39%	6271
	21st to end	Night	21% 11% 4 6% 3 3 3 2 4 5% 38%	6336
February	1st to 10th	Night	22% 12% 4 8% 4 4 4 3 3 5% 32%	2400
	11th to 20th	Night	21% 9% 3 8% 4 3 3 3 4 4 37%	2338
	21st to end	Night	21% 9% 3 6% 5% 4 3 3 5% 5% 37%	1980
March	1st to 10th	Night	18% 13% 3 7% 4 4 4 3 4 5% 36%	5373
	11th to 20th	Night	12% 7% 2 5% 3 3 3 3 5% 6% 48%	5315
	21st to end	Night	14% 9% 3 7% 4 4 4 3 5% 7% 40%	4962
April	1st to 10th	Night	13% 6% 2 5% 4 4 3 4 5% 7% 47%	2000
	11th to 20th	Night	15% 7% 2 5% 3 3 3 3 6% 6% 47%	1975
	21st to end	Night	15% 8% 2 6% 4 4 4 4 6% 8% 40%	2000
May	1st to 10th	Night	18% 9% 3 7% 5% 4 5% 4 6% 7% 31%	4089
	11th to 20th	Night	15% 9% 3 8% 5% 5% 5% 3 7% 8% 32%	4032
	21st to end	Night	14% 7% 3 7% 4 5% 4 4 6% 8% 38%	4334
June	1st to 10th	Night	11% 5% 2 6% 4 3 4 4 5% 9% 46%	1600
	11th to 20th	Night	6% 4 2 4 3 3 3 5% 6% 11% 53%	1600
	21st to end	Night	3 2 1 4 4 4 6% 4 8% 13% 51%	1600
July	1st to 10th	Night	7% 4 2 7% 4 5% 5% 4 6% 9% 46%	3618
	11th to 20th	Night	4 4 2 6% 4 5% 5% 5% 7% 11% 47%	3617
	21st to end	Night	6% 6% 2 9% 6% 5% 6% 6% 8% 13% 35%	4157
August	1st to 10th	Night	4 3 1 4 4 4 4 3 5% 8% 60%	3184
	11th to 20th	Night	4 4 2 5% 4 4 5% 4 7% 10% 51%	3100
	21st to end	Night	4 3 1 3 3 2 3 4 6% 9% 61%	3476
September	1st to 10th	Night	10% 5% 2 5% 4 3 3 3 5% 7% 53%	1900
	11th to 20th	Night	9% 6% 2 6% 4 3 4 3 6% 7% 51%	2029
	21st to end	Night	10% 6% 2 5% 4 4 4 3 4 6% 54%	2090
October	1st to 10th	Night	9% 3 1 5% 3 3 3 2 4 6% 60%	2090
	11th to 20th	Night	15% 5% 2 4 3 3 4 3 4 5% 54%	2246
	21st to end	Night	18% 8% 2 4 3 3 3 3 4 5% 47%	2636
November	1st to 10th	Night	14% 6% 2 5% 3 3 2 2 4 6% 53%	2536
	11th to 20th	Night	13% 7% 2 5% 4 3 3 3 5% 7% 49%	2600
	21st to end	Night	18% 8% 3 4 3 3 3 3 3 5% 47%	2600
December	1st to 10th	Night	17% 10% 2 7% 3 3 4 3 4 5% 42%	4250
	11th to 20th	Night	20% 9% 2 5% 3 4 4 2 4 5% 41%	5090
	21st to end	Night	20% 14% 5% 8% 5% 5% 4 3 4 5% 27%	6996

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	41% 29% 8% 15% 6% 1	3618
	11th to 20th	Day	30% 29% 4 20% 16% 1	3694
	21st to end	Day	35% 29% 7% 12% 13% 5%	4620
February	1st to 10th	Day	19% 61% 4 10% 4 1	2000
	11th to 20th	Day	22% 61% 3 8% 5% 1	1958
	21st to end	Day	18% 61% 3 8% 7% 3	1650
March	1st to 10th	Day	38% 29% 2 13% 12% 6%	4480
	11th to 20th	Day	25% 29% 4 20% 18% 4	4685
	21st to end	Day	28% 30% 7% 21% 15%	5969
April	1st to 10th	Day	19% 62% 4 8% 6% 1	2400
	11th to 20th	Day	18% 62% 4 9% 5% 2	2374
	21st to end	Day	16% 62% 4 10% 6% 1	2400
May	1st to 10th	Day	40% 32% 9% 11% 7%	5842
	11th to 20th	Day	37% 32% 10% 15% 6%	5865
	21st to end	Day	33% 31% 6% 15% 14% 2	6533
June	1st to 10th	Day	16% 62% 4 9% 8% 1	2800
	11th to 20th	Day	13% 63% 5% 10% 7% 1	2800
	21st to end	Day	13% 62% 9% 10% 6%	2800
July	1st to 10th	Day	28% 28% 9% 23% 11%	6291
	11th to 20th	Day	25% 30% 13% 27% 4	6285
	21st to end	Day	33% 29% 16% 18% 5%	6496
August	1st to 10th	Day	15% 37% 10% 21% 17% 1	3821
	11th to 20th	Day	23% 40% 8% 17% 12% 1	3765
	21st to end	Day	13% 38% 7% 26% 16%	4179
September	1st to 10th	Day	10% 60% 5% 14% 8% 3	2280
	11th to 20th	Day	12% 60% 5% 12% 10% 1	2130
	21st to end	Day	15% 60% 4 13% 7% 1	2090
October	1st to 10th	Day	9% 36% 2 10% 36% 6%	3480
	11th to 20th	Day	11% 37% 4 18% 22% 9%	3185
	21st to end	Day	16% 36% 3 19% 22% 4	3212
November	1st to 10th	Day	19% 56% 4 10% 11% 1	1762
	11th to 20th	Day	17% 56% 3 10% 12% 3	1800
	21st to end	Day	21% 56% 3 11% 8% 1	1800
December	1st to 10th	Day	28% 36% 3 20% 12% 1	2930
	11th to 20th	Day	34% 33% 5% 16% 10% 2	3106
	21st to end	Day	44% 28% 8% 15% 5%	3982
January	1st to 10th	Night	40% 28% 7% 17% 8% 1	6348
	11th to 20th	Night	35% 29% 3 16% 15% 2	6271
	21st to end	Night	36% 28% 4 16% 11% 4	6336
February	1st to 10th	Night	22% 61% 3 8% 4 1	2400
	11th to 20th	Night	23% 60% 2 7% 7% 1	2339
	21st to end	Night	18% 61% 3 7% 9% 2	1980
March	1st to 10th	Night	40% 29% 3 10% 13% 6%	5373
	11th to 20th	Night	23% 30% 5% 17% 15% 10%	5315
	21st to end	Night	30% 29% 6% 20% 12% 2	4962
April	1st to 10th	Night	17% 62% 4 10% 7%	2000
	11th to 20th	Night	16% 63% 4 9% 6% 1	1975
	21st to end	Night	16% 62% 3 10% 8% 1	2000
May	1st to 10th	Night	37% 32% 10% 15% 6%	4116
	11th to 20th	Night	37% 32% 11% 14% 6%	4033
	21st to end	Night	34% 32% 8% 18% 8% 1	4342
June	1st to 10th	Night	17% 63% 4 7% 9% 1	1600
	11th to 20th	Night	12% 63% 5% 10% 10% 1	1600
	21st to end	Night	9% 62% 7% 14% 7% 1	1600
July	1st to 10th	Night	27% 29% 9% 21% 13% 1	3580
	11th to 20th	Night	22% 31% 14% 25% 8% 1	3572
	21st to end	Night	31% 30% 16% 18% 5%	4037
August	1st to 10th	Night	13% 37% 9% 26% 14%	3172
	11th to 20th	Night	17% 39% 12% 21% 10% 1	3130
	21st to end	Night	10% 38% 6% 27% 19% 1	3476
September	1st to 10th	Night	9% 61% 4 15% 10% 2	1900
	11th to 20th	Night	10% 60% 4 13% 11% 1	2029
	21st to end	Night	13% 60% 4 13% 9% 1	2090
October	1st to 10th	Night	9% 37% 2 8% 35% 8%	3480
	11th to 20th	Night	9% 36% 2 13% 31% 9%	3732
	21st to end	Night	15% 36% 4 17% 20% 8%	4335
November	1st to 10th	Night	19% 56% 3 11% 10% 2	2536
	11th to 20th	Night	14% 56% 3 11% 12% 4	2600
	21st to end	Night	19% 57% 3 13% 8% 1	2600
December	1st to 10th	Night	29% 36% 4 16% 14% 1	4250
	11th to 20th	Night	30% 32% 6% 18% 14% 1	5092
	21st to end	Night	45% 28% 6% 14% 5% 1	6996

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	28% 17% 36% 15% 4	300
	11th to 20th	Day	28% 20% 36% 14% 2	300
	21st to end	Day	23% 22% 41% 11% 2	330
February	1st to 10th	Day	27% 23% 30% 16% 3 1	300
	11th to 20th	Day	32% 24% 34% 7% 2	300
	21st to end	Day	29% 17% 40% 10% 4	249
March	1st to 10th	Day	27% 18% 40% 12% 3 1	300
	11th to 20th	Day	27% 21% 36% 13% 3	331
	21st to end	Day	26% 19% 34% 16% 5% 1	550
April	1st to 10th	Day	22% 15% 32% 22% 8% 1	500
	11th to 20th	Day	24% 17% 26% 24% 7% 2	492
	21st to end	Day	22% 12% 32% 22% 8% 3	500
May	1st to 10th	Day	21% 16% 26% 26% 9% 3	503
	11th to 20th	Day	19% 9% 23% 28% 15% 6%	527
	21st to end	Day	11% 6% 24% 30% 18% 10%	607
June	1st to 10th	Day	12% 5% 21% 29% 22% 12%	730
	11th to 20th	Day	6% 3 18% 34% 29% 10%	730
	21st to end	Day	6% 3 21% 35% 23% 12%	730
July	1st to 10th	Day	10% 3 12% 28% 29% 18%	721
	11th to 20th	Day	9% 3 13% 28% 35% 13%	718
	21st to end	Day	8% 2 14% 30% 32% 15%	713
August	1st to 10th	Day	11% 2 12% 32% 30% 14%	502
	11th to 20th	Day	12% 3 14% 33% 30% 8%	479
	21st to end	Day	10% 1 9% 26% 34% 21%	539
September	1st to 10th	Day	11% 2 14% 26% 31% 16%	490
	11th to 20th	Day	11% 3 10% 28% 31% 17%	490
	21st to end	Day	17% 8% 18% 25% 22% 11%	490
October	1st to 10th	Day	11% 3 20% 33% 25% 8%	490
	11th to 20th	Day	13% 12% 31% 26% 14% 5%	332
	21st to end	Day	26% 12% 29% 22% 10% 1	330
November	1st to 10th	Day	17% 8% 36% 25% 12% 1	300
	11th to 20th	Day	17% 17% 32% 25% 7% 1	300
	21st to end	Day	24% 11% 35% 20% 8% 1	300
December	1st to 10th	Day	22% 19% 34% 17% 8%	300
	11th to 20th	Day	27% 15% 32% 20% 6%	300
	21st to end	Day	25% 19% 38% 14% 3	330
January	1st to 10th	Night	25% 18% 32% 22% 4	1000
	11th to 20th	Night	28% 18% 32% 19% 3	1000
	21st to end	Night	23% 17% 36% 22% 2	1037
February	1st to 10th	Night	27% 15% 35% 21% 2	800
	11th to 20th	Night	27% 18% 34% 20% 1	783
	21st to end	Night	27% 15% 37% 20% 1	660
March	1st to 10th	Night	23% 15% 32% 26% 5%	800
	11th to 20th	Night	23% 12% 35% 24% 5% 1	785
	21st to end	Night	22% 12% 31% 28% 6% 1	660
April	1st to 10th	Night	16% 12% 35% 29% 8%	600
	11th to 20th	Night	19% 10% 30% 29% 11% 1	593
	21st to end	Night	19% 8% 32% 30% 10% 1	600
May	1st to 10th	Night	21% 7% 31% 26% 14% 1	600
	11th to 20th	Night	13% 6% 20% 39% 19% 2	591
	21st to end	Night	9% 4 16% 41% 27% 4	650
June	1st to 10th	Night	13% 3 16% 36% 28% 4	600
	11th to 20th	Night	8% 1 12% 43% 34% 3	600
	21st to end	Night	4 1 14% 40% 36% 6%	600
July	1st to 10th	Night	7% 2 10% 30% 42% 10%	585
	11th to 20th	Night	7% 2 11% 29% 45% 6%	582
	21st to end	Night	8% 2 10% 34% 38% 8%	657
August	1st to 10th	Night	7% 1 9% 33% 40% 9%	579
	11th to 20th	Night	8% 3 10% 38% 36% 5%	564
	21st to end	Night	9% 1 8% 29% 45% 8%	627
September	1st to 10th	Night	12% 1 12% 31% 38% 5%	570
	11th to 20th	Night	13% 2 10% 31% 37% 7%	699
	21st to end	Night	13% 4 18% 32% 29% 5%	760
October	1st to 10th	Night	11% 5% 17% 33% 29% 5%	760
	11th to 20th	Night	18% 6% 23% 32% 18% 2	760
	21st to end	Night	22% 7% 28% 28% 13% 1	836
November	1st to 10th	Night	16% 8% 28% 34% 13% 2	780
	11th to 20th	Night	16% 13% 33% 29% 10% 1	800
	21st to end	Night	24% 10% 29% 26% 10%	800
December	1st to 10th	Night	26% 13% 30% 26% 5% 1	800
	11th to 20th	Night	24% 10% 33% 26% 6%	930
	21st to end	Night	28% 13% 31% 24% 4	1100

Page generated at 2025-08-02 00:32:27. Version ac07

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