Upstate Stars Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Upstate Stars Observatory clear sky chart from 2005-11-06 to 2024-11-05.

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	18% 10% 4 8% 5% 5% 4 4 5% 7% 31%	101408
	Night	18% 10% 4 8% 5% 4 4 3 5% 6% 32%	97623
Transparency	Day	49% 7% 12% 20% 10% 1	104915
	Night	48% 7% 13% 20% 11% 1	102192
Seeing	Day	26% 18% 27% 17% 9% 3	14842
	Night	25% 18% 25% 23% 9% 1	23990

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% 15% 8% 12% 7% 5% 4 3 5% 5% 24%	2517
	11th to 20th	Day	15% 15% 8% 14% 6% 5% 5% 3 4 4 20%	2520
	21st to end	Day	22% 15% 7% 10% 5% 4 4 3 4 6% 20%	3029
February	1st to 10th	Day	15% 15% 5% 10% 8% 5% 5% 4 5% 5% 22%	1710
	11th to 20th	Day	13% 11% 5% 11% 7% 5% 4 4 4 8% 29%	1781
	21st to end	Day	20% 12% 4 10% 6% 4 3 3 6% 5% 28%	1570
March	1st to 10th	Day	23% 15% 4 9% 5% 3 3 2 4 5% 28%	3116
	11th to 20th	Day	10% 15% 6% 11% 6% 5% 4 3 5% 6% 29%	3416
	21st to end	Day	20% 12% 3 8% 5% 4 3 3 4 5% 32%	4070
April	1st to 10th	Day	18% 14% 4 8% 5% 4 4 3 5% 5% 31%	2280
	11th to 20th	Day	19% 10% 3 7% 5% 5% 4 4 5% 6% 34%	2254
	21st to end	Day	18% 11% 4 7% 5% 5% 4 3 5% 6% 32%	2285
May	1st to 10th	Day	28% 9% 3 6% 4 3 3 3 5% 6% 30%	4257
	11th to 20th	Day	21% 9% 3 8% 6% 6% 5% 4 6% 6% 26%	4398
	21st to end	Day	15% 6% 2 6% 5% 4 6% 5% 6% 8% 38%	4837
June	1st to 10th	Day	17% 6% 3 7% 5% 6% 6% 4 7% 8% 30%	2660
	11th to 20th	Day	17% 8% 3 7% 5% 5% 5% 5% 6% 9% 30%	2660
	21st to end	Day	17% 8% 3 7% 5% 4 4 4 7% 10% 31%	2660
July	1st to 10th	Day	11% 7% 3 7% 6% 5% 5% 5% 7% 9% 34%	4440
	11th to 20th	Day	10% 7% 2 7% 5% 5% 6% 5% 7% 11% 34%	4440
	21st to end	Day	16% 7% 3 7% 5% 6% 5% 5% 6% 8% 32%	4814
August	1st to 10th	Day	22% 7% 3 7% 4 5% 5% 4 6% 8% 29%	4212
	11th to 20th	Day	15% 7% 3 6% 5% 4 6% 5% 8% 9% 31%	3773
	21st to end	Day	18% 4 2 5% 4 5% 5% 4 7% 9% 37%	4180
September	1st to 10th	Day	18% 6% 3 6% 5% 4 4 3 5% 8% 38%	2280
	11th to 20th	Day	15% 6% 2 6% 3 5% 5% 4 5% 7% 44%	2237
	21st to end	Day	21% 7% 3 6% 4 4 4 4 6% 6% 35%	2090
October	1st to 10th	Day	21% 8% 3 7% 4 4 4 4 5% 6% 33%	1914
	11th to 20th	Day	18% 10% 3 6% 4 5% 5% 4 5% 6% 35%	1900
	21st to end	Day	23% 12% 3 7% 4 5% 4 3 5% 6% 27%	1962
November	1st to 10th	Day	15% 9% 3 6% 4 4 4 4 5% 6% 40%	1708
	11th to 20th	Day	18% 13% 4 9% 5% 4 3 3 4 5% 32%	1710
	21st to end	Day	19% 13% 4 8% 5% 4 4 3 5% 5% 28%	1530
December	1st to 10th	Day	20% 15% 5% 12% 5% 5% 3 4 4 5% 21%	1520
	11th to 20th	Day	22% 12% 7% 10% 4 4 2 3 4 5% 27%	1906
	21st to end	Day	20% 17% 8% 11% 6% 4 4 3 4 4 17%	2772
January	1st to 10th	Night	16% 12% 7% 10% 5% 4 4 4 5% 7% 27%	4429
	11th to 20th	Night	14% 15% 6% 15% 7% 5% 4 3 5% 4 22%	4440
	21st to end	Night	22% 13% 5% 11% 8% 4 4 3 4 5% 20%	4624
February	1st to 10th	Night	16% 12% 4 9% 7% 6% 5% 4 6% 6% 27%	2470
	11th to 20th	Night	13% 11% 4 12% 8% 6% 5% 4 7% 7% 25%	2284
	21st to end	Night	19% 11% 4 10% 5% 4 4 3 5% 6% 29%	1884
March	1st to 10th	Night	21% 15% 4 8% 4 3 3 3 4 5% 29%	3724
	11th to 20th	Night	11% 12% 7% 12% 6% 4 3 3 5% 6% 30%	3525
	21st to end	Night	14% 13% 4 9% 5% 4 4 3 4 5% 34%	3548
April	1st to 10th	Night	18% 13% 4 8% 5% 4 4 4 5% 6% 29%	1900
	11th to 20th	Night	19% 10% 4 7% 4 4 4 3 5% 6% 35%	1875
	21st to end	Night	19% 9% 4 7% 4 3 4 3 5% 6% 36%	1895
May	1st to 10th	Night	28% 8% 3 6% 4 3 3 3 4 7% 30%	2711
	11th to 20th	Night	21% 10% 3 7% 5% 3 4 4 5% 6% 32%	2495
	21st to end	Night	17% 9% 2 6% 4 4 4 4 6% 8% 37%	2738
June	1st to 10th	Night	17% 7% 2 7% 4 4 4 3 6% 8% 38%	1520
	11th to 20th	Night	17% 7% 2 5% 5% 3 4 4 5% 9% 41%	1520
	21st to end	Night	14% 5% 2 5% 4 5% 5% 4 7% 9% 42%	1520
July	1st to 10th	Night	13% 5% 3 8% 5% 4 5% 4 6% 9% 38%	2520
	11th to 20th	Night	16% 8% 3 5% 4 3 4 4 6% 9% 38%	2520
	21st to end	Night	18% 7% 2 6% 4 4 5% 3 5% 7% 38%	2739
August	1st to 10th	Night	24% 8% 3 7% 5% 3 4 3 6% 6% 31%	2714
	11th to 20th	Night	18% 8% 3 7% 4 4 4 3 5% 6% 39%	3023
	21st to end	Night	14% 5% 1 5% 4 4 4 3 5% 8% 46%	3476
September	1st to 10th	Night	17% 7% 2 6% 3 4 4 3 4 7% 43%	1900
	11th to 20th	Night	15% 5% 2 5% 3 4 3 3 4 7% 49%	1943
	21st to end	Night	19% 7% 2 6% 4 4 4 3 5% 8% 38%	2090
October	1st to 10th	Night	21% 8% 3 7% 4 3 4 3 5% 5% 37%	2261
	11th to 20th	Night	19% 9% 2 7% 4 3 4 3 4 5% 39%	2280
	21st to end	Night	22% 11% 3 7% 5% 3 4 3 5% 6% 31%	2635
November	1st to 10th	Night	14% 9% 3 7% 4 4 5% 3 5% 6% 41%	2470
	11th to 20th	Night	21% 9% 3 8% 4 4 3 4 5% 6% 33%	2470
	21st to end	Night	15% 11% 4 8% 6% 4 4 4 6% 7% 31%	2648
December	1st to 10th	Night	20% 14% 6% 9% 5% 4 4 4 5% 6% 21%	2660
	11th to 20th	Night	20% 14% 5% 11% 5% 4 4 3 4 5% 25%	3288
	21st to end	Night	23% 14% 6% 10% 5% 4 4 3 4 6% 20%	4884

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	54% 7% 15% 18% 5% 1	2518
	11th to 20th	Day	63% 6% 11% 14% 4 2	2520
	21st to end	Day	62% 6% 11% 14% 6% 1	3029
February	1st to 10th	Day	59% 6% 13% 14% 7%	1710
	11th to 20th	Day	53% 5% 11% 19% 11% 1	1790
	21st to end	Day	55% 6% 12% 17% 8% 1	1570
March	1st to 10th	Day	58% 4 12% 15% 9% 1	3119
	11th to 20th	Day	50% 9% 12% 20% 8% 1	3416
	21st to end	Day	51% 5% 8% 14% 18% 4	4070
April	1st to 10th	Day	54% 6% 8% 20% 10% 3	2280
	11th to 20th	Day	50% 6% 11% 20% 12% 2	2254
	21st to end	Day	52% 5% 10% 18% 12% 4	2285
May	1st to 10th	Day	54% 6% 10% 18% 10% 2	4271
	11th to 20th	Day	54% 9% 10% 18% 7% 1	4402
	21st to end	Day	38% 10% 14% 24% 13% 1	4837
June	1st to 10th	Day	48% 8% 14% 19% 12%	2660
	11th to 20th	Day	48% 8% 14% 20% 9% 1	2660
	21st to end	Day	47% 7% 14% 23% 9%	2660
July	1st to 10th	Day	43% 10% 14% 22% 11% 1	4370
	11th to 20th	Day	40% 9% 16% 22% 11%	4365
	21st to end	Day	48% 8% 14% 18% 11% 1	4661
August	1st to 10th	Day	53% 6% 14% 18% 9%	4198
	11th to 20th	Day	44% 9% 16% 25% 6%	3810
	21st to end	Day	40% 7% 13% 30% 10% 1	4180
September	1st to 10th	Day	44% 6% 11% 24% 13% 1	2280
	11th to 20th	Day	38% 6% 11% 23% 20% 1	2237
	21st to end	Day	47% 6% 11% 19% 14% 2	2090
October	1st to 10th	Day	48% 7% 8% 20% 16% 2	3174
	11th to 20th	Day	41% 5% 9% 22% 15% 7%	3140
	21st to end	Day	38% 5% 16% 25% 13% 3	3213
November	1st to 10th	Day	42% 6% 15% 19% 15% 2	1708
	11th to 20th	Day	54% 4 12% 16% 11% 2	1710
	21st to end	Day	55% 5% 15% 18% 6% 1	1530
December	1st to 10th	Day	62% 6% 13% 11% 7% 1	1520
	11th to 20th	Day	57% 5% 15% 16% 5% 1	1906
	21st to end	Day	68% 6% 9% 12% 6%	2772
January	1st to 10th	Night	51% 6% 17% 18% 7% 1	4429
	11th to 20th	Night	59% 7% 13% 13% 6% 1	4440
	21st to end	Night	61% 7% 11% 14% 6% 1	4624
February	1st to 10th	Night	53% 7% 16% 15% 8% 1	2470
	11th to 20th	Night	53% 6% 14% 17% 9% 1	2286
	21st to end	Night	52% 5% 12% 20% 9% 2	1884
March	1st to 10th	Night	55% 5% 13% 17% 9% 2	3734
	11th to 20th	Night	49% 8% 16% 19% 7% 1	3526
	21st to end	Night	48% 6% 10% 17% 17% 2	3548
April	1st to 10th	Night	54% 6% 9% 18% 11% 2	1900
	11th to 20th	Night	49% 6% 11% 18% 16%	1875
	21st to end	Night	47% 7% 10% 20% 14% 3	1895
May	1st to 10th	Night	53% 6% 9% 20% 9% 2	2717
	11th to 20th	Night	51% 10% 13% 18% 8% 1	2496
	21st to end	Night	42% 10% 13% 22% 12% 1	2739
June	1st to 10th	Night	42% 7% 13% 24% 14% 1	1520
	11th to 20th	Night	39% 8% 17% 24% 11% 1	1520
	21st to end	Night	35% 10% 17% 25% 13%	1520
July	1st to 10th	Night	41% 8% 17% 18% 15% 1	2480
	11th to 20th	Night	41% 7% 14% 25% 12% 1	2472
	21st to end	Night	44% 7% 13% 22% 13% 1	2651
August	1st to 10th	Night	52% 7% 14% 20% 7% 1	2704
	11th to 20th	Night	43% 7% 16% 26% 8%	3052
	21st to end	Night	34% 7% 12% 34% 12%	3476
September	1st to 10th	Night	40% 8% 13% 25% 14% 1	1900
	11th to 20th	Night	35% 6% 10% 24% 23% 1	1943
	21st to end	Night	45% 5% 11% 21% 17% 1	2090
October	1st to 10th	Night	48% 7% 9% 21% 14% 1	3768
	11th to 20th	Night	38% 6% 12% 21% 17% 7%	3779
	21st to end	Night	39% 6% 16% 25% 12% 1	4334
November	1st to 10th	Night	42% 6% 12% 21% 17% 2	2470
	11th to 20th	Night	48% 6% 13% 18% 11% 3	2470
	21st to end	Night	48% 6% 18% 20% 7%	2648
December	1st to 10th	Night	58% 8% 14% 15% 5%	2660
	11th to 20th	Night	57% 6% 14% 15% 8%	3288
	21st to end	Night	61% 7% 13% 13% 6%	4884

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	34% 24% 28% 12% 1 1	180
	11th to 20th	Day	42% 24% 24% 7% 3	180
	21st to end	Day	29% 27% 32% 8% 4	271
February	1st to 10th	Day	33% 33% 28% 6% 1	270
	11th to 20th	Day	36% 32% 23% 7% 1	389
	21st to end	Day	38% 22% 27% 10% 2	382
March	1st to 10th	Day	33% 22% 28% 14% 3	460
	11th to 20th	Day	33% 26% 26% 12% 3 1	460
	21st to end	Day	35% 27% 23% 9% 5% 1	506
April	1st to 10th	Day	37% 23% 25% 11% 4 1	460
	11th to 20th	Day	34% 22% 23% 12% 6% 3	452
	21st to end	Day	30% 20% 32% 10% 5% 2	460
May	1st to 10th	Day	38% 17% 26% 11% 4 3	463
	11th to 20th	Day	22% 20% 32% 18% 5% 3	487
	21st to end	Day	22% 11% 29% 24% 12% 3	529
June	1st to 10th	Day	21% 14% 32% 20% 10% 3	490
	11th to 20th	Day	22% 15% 25% 24% 12% 2	490
	21st to end	Day	20% 16% 33% 20% 11% 1	490
July	1st to 10th	Day	13% 10% 30% 27% 15% 4	485
	11th to 20th	Day	14% 8% 31% 30% 15% 3	484
	21st to end	Day	17% 11% 35% 23% 12% 3	532
August	1st to 10th	Day	15% 13% 26% 24% 16% 6%	486
	11th to 20th	Day	17% 9% 26% 25% 17% 6%	479
	21st to end	Day	18% 10% 28% 22% 15% 7%	539
September	1st to 10th	Day	24% 10% 23% 21% 15% 7%	490
	11th to 20th	Day	14% 13% 23% 25% 14% 12%	490
	21st to end	Day	25% 12% 28% 19% 12% 4	490
October	1st to 10th	Day	29% 13% 24% 18% 13% 3	490
	11th to 20th	Day	25% 19% 26% 21% 8% 1	490
	21st to end	Day	32% 18% 26% 18% 6% 1	472
November	1st to 10th	Day	27% 20% 22% 20% 9% 2	378
	11th to 20th	Day	31% 24% 24% 17% 4 1	370
	21st to end	Day	31% 24% 31% 12% 2	190
December	1st to 10th	Day	34% 26% 24% 10% 5% 1	180
	11th to 20th	Day	41% 21% 28% 8% 2	180
	21st to end	Day	35% 29% 24% 10% 2 1	198
January	1st to 10th	Night	27% 27% 30% 14% 2	760
	11th to 20th	Night	31% 21% 27% 18% 3	760
	21st to end	Night	22% 27% 33% 15% 3	836
February	1st to 10th	Night	29% 22% 33% 15% 1	760
	11th to 20th	Night	28% 29% 30% 12% 1	743
	21st to end	Night	35% 23% 24% 15% 3	628
March	1st to 10th	Night	29% 22% 31% 14% 3	760
	11th to 20th	Night	25% 27% 27% 18% 3	760
	21st to end	Night	25% 24% 30% 15% 5%	836
April	1st to 10th	Night	29% 21% 29% 16% 4	760
	11th to 20th	Night	25% 21% 28% 20% 6%	751
	21st to end	Night	27% 20% 25% 21% 7%	755
May	1st to 10th	Night	31% 14% 23% 25% 6% 1	499
	11th to 20th	Night	21% 12% 29% 30% 8%	374
	21st to end	Night	19% 9% 22% 34% 15% 1	411
June	1st to 10th	Night	19% 9% 25% 32% 14% 1	380
	11th to 20th	Night	19% 8% 23% 34% 15% 1	380
	21st to end	Night	14% 5% 25% 41% 15%	380
July	1st to 10th	Night	15% 7% 20% 38% 18% 2	370
	11th to 20th	Night	15% 5% 21% 39% 18% 2	368
	21st to end	Night	16% 6% 20% 39% 17% 1	416
August	1st to 10th	Night	16% 4 22% 33% 23% 2	495
	11th to 20th	Night	17% 6% 16% 38% 19% 4	700
	21st to end	Night	19% 6% 17% 34% 24% 2	836
September	1st to 10th	Night	20% 7% 24% 27% 19% 2	760
	11th to 20th	Night	18% 7% 21% 27% 20% 7%	760
	21st to end	Night	22% 12% 21% 29% 14% 3	760
October	1st to 10th	Night	27% 13% 21% 21% 16% 2	760
	11th to 20th	Night	24% 14% 26% 27% 8%	760
	21st to end	Night	28% 19% 27% 20% 5%	836
November	1st to 10th	Night	20% 21% 26% 25% 8% 1	760
	11th to 20th	Night	28% 21% 21% 22% 7% 1	760
	21st to end	Night	23% 22% 29% 20% 5% 1	760
December	1st to 10th	Night	31% 26% 24% 16% 4	760
	11th to 20th	Night	31% 24% 26% 17% 3	760
	21st to end	Night	31% 25% 26% 15% 2	836

Page generated at 2024-11-03 02:11:13. Version ac07

Copyright © 2024 Attilla Danko.