Albany
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Albany clear sky chart from 2005-11-06 to 2024-11-04.

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	16% 8% 3 8% 5% 5% 5% 4 6% 7% 34%	101360
	Night	17% 9% 3 8% 5% 5% 4 4 5% 6% 33%	97642
Transparency	Day	46% 9% 14% 20% 11% 1	104867
	Night	48% 9% 13% 19% 10% 1	102224
Seeing	Day	21% 17% 29% 21% 9% 3	14835
	Night	21% 15% 31% 25% 7% 1	23873

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	14% 10% 4 10% 6% 5% 5% 5% 5% 6% 29%	2517
	11th to 20th	Day	16% 12% 5% 12% 6% 5% 4 4 5% 6% 23%	2520
	21st to end	Day	19% 12% 5% 9% 6% 5% 5% 4 6% 6% 23%	2868
February	1st to 10th	Day	16% 12% 3 7% 6% 6% 5% 5% 7% 8% 26%	1710
	11th to 20th	Day	12% 13% 4 10% 5% 5% 6% 4 5% 6% 29%	1825
	21st to end	Day	18% 11% 4 8% 6% 5% 4 4 5% 6% 29%	1570
March	1st to 10th	Day	23% 12% 5% 9% 5% 3 3 3 4 5% 28%	3116
	11th to 20th	Day	13% 14% 3 8% 6% 4 4 3 5% 6% 33%	3288
	21st to end	Day	20% 8% 2 8% 5% 4 5% 3 4 5% 35%	4161
April	1st to 10th	Day	18% 10% 4 8% 5% 4 4 4 5% 6% 34%	2280
	11th to 20th	Day	17% 7% 3 7% 5% 4 5% 4 5% 6% 37%	2254
	21st to end	Day	19% 8% 3 7% 5% 5% 5% 3 6% 7% 33%	2365
May	1st to 10th	Day	23% 9% 3 8% 4 4 4 3 5% 6% 30%	4170
	11th to 20th	Day	17% 8% 3 8% 5% 5% 5% 4 6% 7% 33%	4398
	21st to end	Day	11% 5% 2 6% 5% 4 5% 4 6% 9% 42%	4837
June	1st to 10th	Day	14% 6% 2 8% 6% 6% 5% 5% 7% 8% 33%	2660
	11th to 20th	Day	14% 6% 3 6% 5% 5% 5% 6% 7% 10% 34%	2660
	21st to end	Day	15% 7% 3 7% 5% 5% 5% 5% 6% 7% 35%	2660
July	1st to 10th	Day	9% 6% 2 7% 6% 5% 6% 5% 7% 10% 37%	4440
	11th to 20th	Day	9% 6% 2 7% 6% 6% 6% 5% 7% 9% 37%	4440
	21st to end	Day	12% 6% 3 7% 6% 5% 6% 4 7% 9% 35%	4814
August	1st to 10th	Day	15% 7% 3 8% 6% 5% 6% 4 6% 8% 32%	4386
	11th to 20th	Day	12% 7% 2 8% 5% 6% 6% 4 8% 9% 33%	3730
	21st to end	Day	10% 6% 2 7% 4 5% 5% 5% 7% 10% 39%	4180
September	1st to 10th	Day	13% 5% 2 6% 4 4 5% 4 6% 8% 44%	2280
	11th to 20th	Day	12% 6% 2 5% 4 4 4 3 5% 8% 48%	2191
	21st to end	Day	16% 5% 2 6% 4 4 6% 4 6% 7% 41%	2090
October	1st to 10th	Day	18% 8% 3 8% 5% 5% 4 3 4 5% 35%	1986
	11th to 20th	Day	16% 7% 2 8% 4 4 4 4 6% 6% 40%	1900
	21st to end	Day	24% 8% 3 7% 5% 4 4 4 5% 6% 31%	1890
November	1st to 10th	Day	14% 8% 3 6% 4 4 4 4 6% 7% 42%	1698
	11th to 20th	Day	16% 9% 2 8% 5% 5% 5% 3 6% 6% 36%	1710
	21st to end	Day	18% 10% 3 6% 4 6% 5% 4 6% 6% 33%	1568
December	1st to 10th	Day	18% 13% 4 8% 6% 6% 5% 4 5% 6% 25%	1520
	11th to 20th	Day	23% 12% 3 7% 4 4 3 2 4 5% 32%	1906
	21st to end	Day	25% 16% 4 9% 6% 5% 4 2 4 5% 21%	2772
January	1st to 10th	Night	16% 12% 4 9% 5% 5% 5% 3 5% 5% 31%	4429
	11th to 20th	Night	14% 15% 4 12% 6% 5% 4 4 5% 5% 27%	4440
	21st to end	Night	23% 12% 4 10% 6% 5% 4 3 4 4 25%	4784
February	1st to 10th	Night	16% 12% 4 9% 7% 5% 4 4 5% 5% 28%	2470
	11th to 20th	Night	12% 12% 5% 10% 7% 6% 5% 4 6% 6% 29%	2239
	21st to end	Night	17% 11% 4 10% 5% 5% 4 4 5% 6% 29%	1884
March	1st to 10th	Night	24% 11% 4 9% 5% 4 4 3 4 5% 26%	3724
	11th to 20th	Night	17% 12% 3 7% 6% 5% 4 3 5% 5% 33%	3655
	21st to end	Night	16% 11% 3 9% 6% 4 4 4 4 5% 33%	3471
April	1st to 10th	Night	18% 11% 3 7% 4 5% 5% 3 5% 7% 32%	1900
	11th to 20th	Night	20% 8% 2 8% 5% 4 4 4 5% 6% 35%	1875
	21st to end	Night	20% 6% 3 7% 4 4 4 3 6% 6% 37%	1814
May	1st to 10th	Night	23% 9% 4 8% 4 5% 4 3 5% 5% 31%	2784
	11th to 20th	Night	17% 8% 3 9% 7% 6% 6% 4 6% 6% 29%	2495
	21st to end	Night	12% 6% 2 8% 5% 5% 5% 4 6% 9% 39%	2738
June	1st to 10th	Night	16% 6% 2 5% 6% 5% 4 4 5% 7% 39%	1520
	11th to 20th	Night	14% 6% 2 6% 4 4 5% 5% 7% 9% 39%	1520
	21st to end	Night	13% 4 2 6% 5% 5% 4 4 6% 9% 42%	1520
July	1st to 10th	Night	9% 7% 2 8% 6% 6% 5% 5% 6% 7% 38%	2520
	11th to 20th	Night	14% 6% 3 7% 5% 4 6% 4 6% 9% 38%	2520
	21st to end	Night	12% 8% 3 7% 6% 4 5% 4 6% 8% 38%	2739
August	1st to 10th	Night	20% 7% 3 7% 5% 4 4 4 5% 8% 33%	2521
	11th to 20th	Night	14% 8% 3 7% 5% 5% 5% 4 6% 7% 37%	3084
	21st to end	Night	10% 6% 2 7% 4 4 4 4 6% 8% 43%	3476
September	1st to 10th	Night	14% 8% 3 7% 4 3 3 3 6% 7% 42%	1900
	11th to 20th	Night	14% 5% 2 4 3 3 3 2 5% 8% 51%	1988
	21st to end	Night	15% 6% 2 6% 5% 5% 4 4 5% 7% 41%	2090
October	1st to 10th	Night	18% 8% 3 7% 5% 5% 4 4 5% 5% 36%	2190
	11th to 20th	Night	16% 6% 2 7% 4 5% 4 4 5% 6% 40%	2280
	21st to end	Night	23% 8% 2 7% 5% 4 4 3 5% 7% 31%	2707
November	1st to 10th	Night	15% 8% 2 7% 4 4 4 3 4 7% 41%	2453
	11th to 20th	Night	17% 9% 3 7% 4 5% 5% 4 5% 6% 36%	2470
	21st to end	Night	16% 8% 3 7% 6% 5% 4 4 6% 7% 34%	2610
December	1st to 10th	Night	19% 13% 4 8% 5% 4 5% 4 5% 7% 27%	2660
	11th to 20th	Night	23% 10% 4 7% 5% 5% 5% 3 5% 6% 28%	3288
	21st to end	Night	27% 14% 4 8% 5% 4 4 3 4 5% 22%	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	48% 13% 15% 19% 5%	2518
	11th to 20th	Day	59% 10% 12% 14% 5% 1	2520
	21st to end	Day	59% 10% 12% 13% 4 1	2868
February	1st to 10th	Day	54% 10% 13% 15% 7% 1	1710
	11th to 20th	Day	53% 8% 11% 18% 8% 1	1834
	21st to end	Day	55% 9% 11% 15% 10% 1	1570
March	1st to 10th	Day	57% 8% 13% 14% 7% 1	3119
	11th to 20th	Day	44% 14% 18% 15% 8% 2	3288
	21st to end	Day	48% 9% 9% 15% 17% 2	4161
April	1st to 10th	Day	52% 7% 8% 21% 10% 2	2280
	11th to 20th	Day	46% 8% 11% 19% 14% 2	2254
	21st to end	Day	49% 8% 10% 17% 13% 3	2365
May	1st to 10th	Day	52% 9% 12% 16% 9% 1	4184
	11th to 20th	Day	45% 11% 16% 18% 8% 1	4402
	21st to end	Day	34% 12% 16% 24% 14% 1	4837
June	1st to 10th	Day	45% 11% 14% 19% 10% 1	2660
	11th to 20th	Day	43% 10% 16% 19% 12% 1	2660
	21st to end	Day	46% 9% 14% 20% 10% 1	2660
July	1st to 10th	Day	40% 9% 14% 23% 14% 1	4370
	11th to 20th	Day	41% 8% 17% 23% 11%	4365
	21st to end	Day	44% 8% 17% 18% 12%	4661
August	1st to 10th	Day	48% 9% 15% 19% 9% 1	4372
	11th to 20th	Day	44% 9% 17% 25% 5%	3766
	21st to end	Day	36% 9% 17% 27% 10% 1	4180
September	1st to 10th	Day	37% 9% 14% 25% 14% 1	2280
	11th to 20th	Day	34% 8% 13% 24% 20% 1	2191
	21st to end	Day	39% 9% 13% 24% 13% 2	2090
October	1st to 10th	Day	45% 7% 8% 22% 17% 1	3298
	11th to 20th	Day	37% 7% 13% 27% 16%	3140
	21st to end	Day	38% 7% 15% 26% 13% 1	3090
November	1st to 10th	Day	40% 8% 15% 25% 11% 1	1698
	11th to 20th	Day	47% 9% 11% 18% 12% 1	1710
	21st to end	Day	49% 10% 15% 19% 6% 1	1568
December	1st to 10th	Day	59% 9% 12% 14% 6% 1	1520
	11th to 20th	Day	53% 8% 15% 16% 6%	1906
	21st to end	Day	64% 9% 9% 14% 4	2772
January	1st to 10th	Night	49% 12% 14% 16% 8% 1	4429
	11th to 20th	Night	55% 9% 13% 14% 7% 1	4440
	21st to end	Night	61% 8% 12% 12% 5% 1	4784
February	1st to 10th	Night	56% 8% 13% 15% 7% 1	2470
	11th to 20th	Night	53% 8% 14% 16% 8% 1	2241
	21st to end	Night	51% 10% 13% 16% 8% 2	1884
March	1st to 10th	Night	54% 11% 11% 16% 8% 1	3734
	11th to 20th	Night	49% 11% 14% 18% 7% 1	3656
	21st to end	Night	49% 9% 9% 15% 15% 3	3471
April	1st to 10th	Night	52% 7% 12% 18% 10% 1	1900
	11th to 20th	Night	48% 8% 10% 19% 14% 1	1875
	21st to end	Night	46% 8% 11% 17% 14% 4	1814
May	1st to 10th	Night	53% 8% 13% 13% 11% 1	2790
	11th to 20th	Night	49% 12% 15% 15% 7% 2	2496
	21st to end	Night	38% 12% 15% 19% 15% 1	2739
June	1st to 10th	Night	43% 8% 14% 23% 12% 1	1520
	11th to 20th	Night	39% 11% 16% 22% 11% 1	1520
	21st to end	Night	38% 10% 16% 23% 13% 1	1520
July	1st to 10th	Night	43% 7% 16% 18% 16% 1	2480
	11th to 20th	Night	41% 9% 15% 22% 13%	2472
	21st to end	Night	43% 7% 15% 24% 11% 1	2651
August	1st to 10th	Night	49% 8% 15% 20% 7% 1	2511
	11th to 20th	Night	44% 8% 18% 22% 9%	3114
	21st to end	Night	36% 8% 15% 31% 10% 1	3476
September	1st to 10th	Night	41% 7% 13% 25% 14% 1	1900
	11th to 20th	Night	31% 7% 13% 27% 21% 1	1988
	21st to end	Night	40% 9% 12% 22% 16% 1	2090
October	1st to 10th	Night	49% 6% 12% 21% 11% 1	3658
	11th to 20th	Night	35% 7% 13% 26% 19% 1	3779
	21st to end	Night	41% 7% 14% 28% 10% 1	4457
November	1st to 10th	Night	42% 8% 12% 20% 16% 2	2453
	11th to 20th	Night	47% 8% 13% 19% 11% 2	2470
	21st to end	Night	48% 9% 18% 18% 7%	2610
December	1st to 10th	Night	55% 10% 14% 15% 5%	2660
	11th to 20th	Night	54% 9% 14% 14% 8%	3288
	21st to end	Night	61% 9% 11% 14% 4	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	23% 29% 29% 13% 4 1	180
	11th to 20th	Day	34% 26% 23% 14% 2 1	180
	21st to end	Day	23% 26% 32% 14% 4 1	225
February	1st to 10th	Day	30% 29% 32% 8% 1	270
	11th to 20th	Day	29% 28% 31% 11% 2	433
	21st to end	Day	29% 23% 32% 14% 2	382
March	1st to 10th	Day	27% 22% 32% 16% 3	460
	11th to 20th	Day	28% 25% 28% 16% 3 1	460
	21st to end	Day	32% 23% 23% 14% 6% 2	506
April	1st to 10th	Day	29% 25% 23% 16% 5% 1	460
	11th to 20th	Day	25% 26% 27% 15% 6% 1	452
	21st to end	Day	25% 21% 31% 17% 5% 2	460
May	1st to 10th	Day	27% 18% 31% 15% 7% 2	463
	11th to 20th	Day	19% 15% 35% 22% 8% 2	487
	21st to end	Day	16% 12% 31% 26% 11% 3	529
June	1st to 10th	Day	16% 14% 35% 21% 12% 1	490
	11th to 20th	Day	15% 14% 30% 26% 13% 2	490
	21st to end	Day	17% 13% 32% 24% 11% 2	490
July	1st to 10th	Day	13% 10% 29% 30% 14% 4	485
	11th to 20th	Day	11% 7% 32% 30% 17% 2	484
	21st to end	Day	12% 8% 34% 29% 15% 2	532
August	1st to 10th	Day	13% 7% 28% 31% 17% 5%	486
	11th to 20th	Day	14% 5% 29% 29% 16% 7%	479
	21st to end	Day	11% 11% 30% 26% 17% 6%	539
September	1st to 10th	Day	17% 11% 23% 25% 17% 7%	490
	11th to 20th	Day	13% 11% 24% 22% 16% 13%	490
	21st to end	Day	18% 11% 26% 26% 15% 5%	490
October	1st to 10th	Day	22% 14% 26% 21% 12% 4	490
	11th to 20th	Day	19% 17% 30% 23% 10% 2	490
	21st to end	Day	28% 16% 27% 22% 5% 1	433
November	1st to 10th	Day	24% 17% 24% 21% 12% 2	374
	11th to 20th	Day	23% 24% 29% 17% 6% 1	370
	21st to end	Day	26% 23% 27% 21% 3	228
December	1st to 10th	Day	22% 28% 34% 11% 5% 1	180
	11th to 20th	Day	28% 26% 33% 12% 2	180
	21st to end	Day	25% 24% 35% 14% 2 1	198
January	1st to 10th	Night	21% 19% 39% 18% 2	760
	11th to 20th	Night	26% 22% 31% 19% 2	760
	21st to end	Night	20% 21% 38% 19% 2	836
February	1st to 10th	Night	24% 19% 38% 17% 1	760
	11th to 20th	Night	21% 24% 37% 17% 1	743
	21st to end	Night	26% 22% 32% 17% 3	628
March	1st to 10th	Night	24% 22% 35% 17% 2	760
	11th to 20th	Night	25% 22% 34% 17% 2	760
	21st to end	Night	24% 22% 32% 18% 4	836
April	1st to 10th	Night	24% 21% 32% 21% 2	760
	11th to 20th	Night	24% 19% 32% 19% 5%	751
	21st to end	Night	22% 20% 31% 23% 4	674
May	1st to 10th	Night	24% 18% 30% 22% 6%	546
	11th to 20th	Night	18% 15% 34% 27% 6% 1	374
	21st to end	Night	12% 11% 31% 37% 9%	411
June	1st to 10th	Night	18% 7% 32% 32% 10% 1	380
	11th to 20th	Night	15% 9% 31% 36% 10%	380
	21st to end	Night	13% 6% 30% 41% 11% 1	380
July	1st to 10th	Night	13% 5% 24% 43% 15% 1	370
	11th to 20th	Night	13% 5% 22% 43% 15% 1	368
	21st to end	Night	12% 4 23% 49% 11% 1	416
August	1st to 10th	Night	14% 2 22% 47% 15% 1	380
	11th to 20th	Night	13% 5% 23% 36% 19% 3	737
	21st to end	Night	15% 6% 24% 35% 19% 2	836
September	1st to 10th	Night	18% 6% 28% 32% 14% 2	760
	11th to 20th	Night	17% 7% 25% 28% 19% 4	760
	21st to end	Night	16% 7% 30% 32% 13% 2	760
October	1st to 10th	Night	22% 11% 25% 28% 13% 2	760
	11th to 20th	Night	18% 12% 32% 30% 8%	760
	21st to end	Night	28% 15% 31% 22% 4	836
November	1st to 10th	Night	20% 15% 34% 23% 7%	755
	11th to 20th	Night	22% 17% 34% 20% 6% 1	760
	21st to end	Night	22% 19% 31% 23% 5%	760
December	1st to 10th	Night	25% 21% 35% 15% 4	760
	11th to 20th	Night	27% 18% 30% 22% 3	760
	21st to end	Night	29% 20% 33% 17% 2	836

Page generated at 2024-11-01 22:47:40. Version ac07

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