Stokes Starparty
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Stokes Starparty clear sky chart from 2005-11-06 to 2024-11-30.

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% 8% 3 6% 4 4 4 4 5% 7% 37%	101611
	Night	17% 8% 2 6% 4 4 4 3 5% 7% 40%	98001
Transparency	Day	44% 6% 11% 22% 14% 2	105130
	Night	43% 6% 12% 23% 15% 2	102571
Seeing	Day	24% 17% 28% 19% 9% 3	14983
	Night	22% 15% 29% 25% 9% 1	24179

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% 3 5% 4 4 4 3 4 6% 42%	2517
	11th to 20th	Day	15% 11% 6% 9% 6% 5% 4 3 4 5% 32%	2520
	21st to end	Day	21% 11% 4 6% 5% 4 4 3 5% 6% 31%	3060
February	1st to 10th	Day	16% 9% 3 8% 5% 5% 5% 3 5% 7% 34%	1710
	11th to 20th	Day	13% 9% 3 7% 5% 5% 4 3 5% 6% 40%	1805
	21st to end	Day	19% 10% 3 7% 4 4 4 4 5% 6% 35%	1570
March	1st to 10th	Day	26% 11% 3 6% 4 3 3 2 4 5% 34%	3116
	11th to 20th	Day	10% 8% 3 8% 5% 5% 4 4 6% 7% 40%	3411
	21st to end	Day	21% 9% 2 5% 4 3 3 3 4 5% 41%	4088
April	1st to 10th	Day	18% 9% 2 6% 5% 4 4 3 5% 6% 37%	2280
	11th to 20th	Day	18% 8% 2 5% 4 5% 4 3 4 6% 40%	2254
	21st to end	Day	18% 6% 2 6% 5% 5% 5% 4 6% 6% 38%	2280
May	1st to 10th	Day	28% 8% 3 5% 4 4 4 3 4 7% 31%	4186
	11th to 20th	Day	23% 9% 3 7% 5% 4 5% 3 5% 6% 29%	4398
	21st to end	Day	13% 5% 2 5% 4 4 5% 4 6% 9% 42%	4837
June	1st to 10th	Day	15% 6% 2 7% 5% 6% 5% 5% 6% 9% 36%	2660
	11th to 20th	Day	16% 6% 3 6% 5% 5% 5% 5% 7% 9% 34%	2660
	21st to end	Day	13% 5% 3 7% 6% 5% 5% 4 6% 10% 38%	2660
July	1st to 10th	Day	10% 6% 2 8% 5% 6% 6% 5% 7% 10% 35%	4440
	11th to 20th	Day	10% 6% 2 6% 5% 5% 6% 5% 7% 10% 38%	4440
	21st to end	Day	14% 8% 3 7% 6% 5% 5% 4 6% 7% 33%	4814
August	1st to 10th	Day	22% 5% 2 7% 5% 5% 6% 4 7% 8% 30%	4182
	11th to 20th	Day	14% 6% 2 7% 4 4 6% 4 6% 8% 40%	3738
	21st to end	Day	14% 6% 2 5% 3 4 4 3 5% 9% 46%	4180
September	1st to 10th	Day	16% 6% 2 6% 4 4 5% 4 5% 6% 43%	2280
	11th to 20th	Day	13% 5% 2 4 3 4 3 3 5% 7% 50%	2230
	21st to end	Day	18% 7% 2 7% 4 4 5% 3 5% 7% 38%	2090
October	1st to 10th	Day	21% 6% 2 6% 4 3 4 3 4 7% 39%	1930
	11th to 20th	Day	14% 7% 2 6% 4 3 4 3 5% 7% 43%	1900
	21st to end	Day	22% 7% 1 5% 4 4 5% 4 5% 6% 39%	1968
November	1st to 10th	Day	14% 7% 2 5% 3 3 3 2 4 6% 52%	1761
	11th to 20th	Day	18% 8% 2 4 3 3 3 4 6% 7% 43%	1800
	21st to end	Day	17% 8% 2 5% 5% 4 5% 5% 5% 7% 38%	1648
December	1st to 10th	Day	18% 10% 4 7% 4 5% 4 4 5% 6% 34%	1520
	11th to 20th	Day	21% 8% 3 7% 4 3 4 3 5% 6% 37%	1906
	21st to end	Day	20% 13% 5% 9% 6% 5% 5% 4 4 6% 25%	2772
January	1st to 10th	Night	16% 8% 2 5% 5% 4 4 3 6% 6% 40%	4429
	11th to 20th	Night	14% 10% 5% 9% 5% 4 4 3 4 6% 36%	4440
	21st to end	Night	23% 11% 3 7% 4 3 3 3 5% 6% 32%	4593
February	1st to 10th	Night	17% 8% 2 6% 4 4 4 3 5% 6% 40%	2470
	11th to 20th	Night	15% 8% 2 7% 4 5% 4 4 5% 7% 39%	2261
	21st to end	Night	18% 9% 2 6% 5% 4 4 3 5% 5% 39%	1884
March	1st to 10th	Night	23% 11% 3 6% 4 3 3 3 5% 5% 35%	3724
	11th to 20th	Night	12% 7% 3 6% 4 4 4 4 6% 7% 43%	3544
	21st to end	Night	16% 9% 3 7% 4 4 3 3 4 5% 41%	3543
April	1st to 10th	Night	17% 8% 3 7% 5% 5% 4 4 5% 7% 35%	1900
	11th to 20th	Night	19% 7% 2 6% 4 4 4 4 5% 7% 38%	1875
	21st to end	Night	19% 6% 2 5% 4 4 4 4 5% 6% 40%	1900
May	1st to 10th	Night	27% 9% 3 6% 4 3 3 3 4 7% 31%	2780
	11th to 20th	Night	25% 9% 2 7% 4 4 4 3 5% 5% 33%	2495
	21st to end	Night	13% 6% 2 5% 5% 4 4 4 7% 9% 40%	2738
June	1st to 10th	Night	17% 6% 2 5% 4 5% 3 3 4 8% 43%	1520
	11th to 20th	Night	13% 6% 2 5% 4 4 5% 4 6% 8% 42%	1520
	21st to end	Night	12% 4 2 6% 3 3 4 4 6% 9% 45%	1520
July	1st to 10th	Night	10% 5% 2 6% 5% 5% 5% 4 6% 10% 41%	2520
	11th to 20th	Night	12% 6% 2 6% 3 5% 6% 4 6% 9% 41%	2520
	21st to end	Night	18% 6% 2 5% 4 4 5% 4 6% 8% 38%	2739
August	1st to 10th	Night	22% 5% 3 6% 4 5% 4 4 5% 7% 34%	2745
	11th to 20th	Night	16% 7% 2 6% 4 4 5% 3 5% 6% 42%	3058
	21st to end	Night	13% 4 2 4 4 4 3 3 5% 8% 50%	3476
September	1st to 10th	Night	16% 4 1 5% 4 3 4 3 5% 7% 47%	1900
	11th to 20th	Night	14% 5% 2 4 3 4 3 3 4 6% 52%	1949
	21st to end	Night	18% 6% 3 5% 4 3 3 3 4 6% 44%	2090
October	1st to 10th	Night	22% 6% 2 5% 4 4 4 2 4 6% 42%	2247
	11th to 20th	Night	17% 6% 1 5% 3 3 3 3 4 6% 47%	2280
	21st to end	Night	21% 7% 2 4 3 2 3 3 5% 6% 43%	2628
November	1st to 10th	Night	13% 6% 2 5% 3 4 4 3 5% 6% 50%	2537
	11th to 20th	Night	19% 8% 2 4 3 3 3 3 5% 5% 45%	2600
	21st to end	Night	14% 7% 2 6% 4 4 4 4 5% 7% 43%	2744
December	1st to 10th	Night	19% 8% 2 5% 5% 5% 5% 4 5% 7% 35%	2660
	11th to 20th	Night	19% 9% 2 5% 4 5% 5% 4 5% 6% 36%	3288
	21st to end	Night	22% 11% 4 7% 4 4 4 3 5% 6% 31%	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	43% 5% 11% 31% 8% 2	2518
	11th to 20th	Day	53% 6% 9% 20% 10% 2	2520
	21st to end	Day	54% 6% 10% 20% 10% 1	3060
February	1st to 10th	Day	50% 5% 12% 19% 13% 1	1710
	11th to 20th	Day	46% 5% 9% 22% 16% 2	1814
	21st to end	Day	50% 5% 10% 21% 12% 3	1570
March	1st to 10th	Day	54% 4 9% 22% 10% 2	3119
	11th to 20th	Day	39% 9% 11% 28% 11% 2	3411
	21st to end	Day	46% 4 8% 15% 23% 5%	4088
April	1st to 10th	Day	48% 5% 9% 20% 14% 4	2280
	11th to 20th	Day	45% 5% 11% 20% 16% 3	2254
	21st to end	Day	46% 6% 9% 21% 15% 4	2280
May	1st to 10th	Day	53% 6% 11% 16% 11% 2	4200
	11th to 20th	Day	55% 7% 11% 18% 8% 1	4402
	21st to end	Day	35% 9% 12% 25% 16% 3	4837
June	1st to 10th	Day	44% 8% 12% 21% 14% 1	2660
	11th to 20th	Day	44% 8% 13% 23% 10% 2	2660
	21st to end	Day	42% 7% 13% 24% 14%	2660
July	1st to 10th	Day	44% 8% 13% 20% 14% 1	4370
	11th to 20th	Day	39% 8% 17% 22% 13% 1	4365
	21st to end	Day	48% 7% 11% 18% 14% 2	4661
August	1st to 10th	Day	51% 8% 13% 19% 9%	4168
	11th to 20th	Day	39% 7% 15% 27% 11% 1	3774
	21st to end	Day	35% 5% 11% 31% 15% 1	4180
September	1st to 10th	Day	41% 7% 11% 22% 18% 2	2280
	11th to 20th	Day	35% 4 10% 23% 24% 3	2230
	21st to end	Day	45% 6% 10% 19% 19% 2	2090
October	1st to 10th	Day	41% 5% 8% 18% 23% 4	3203
	11th to 20th	Day	32% 5% 9% 27% 25% 3	3140
	21st to end	Day	30% 4 15% 25% 22% 3	3219
November	1st to 10th	Day	36% 4 12% 25% 19% 3	1761
	11th to 20th	Day	41% 4 10% 24% 18% 3	1800
	21st to end	Day	44% 8% 12% 25% 10% 2	1648
December	1st to 10th	Day	50% 6% 15% 16% 12% 2	1520
	11th to 20th	Day	47% 6% 15% 22% 9% 1	1906
	21st to end	Day	59% 8% 9% 17% 8%	2772
January	1st to 10th	Night	41% 7% 11% 28% 10% 3	4429
	11th to 20th	Night	48% 7% 11% 22% 11% 2	4440
	21st to end	Night	52% 6% 9% 21% 10% 1	4593
February	1st to 10th	Night	45% 5% 14% 22% 12% 1	2470
	11th to 20th	Night	44% 5% 10% 20% 17% 4	2263
	21st to end	Night	46% 4 8% 23% 15% 3	1884
March	1st to 10th	Night	51% 5% 10% 21% 11% 2	3734
	11th to 20th	Night	37% 7% 15% 26% 14% 2	3545
	21st to end	Night	45% 4 8% 18% 20% 5%	3543
April	1st to 10th	Night	49% 6% 10% 20% 14% 3	1900
	11th to 20th	Night	46% 5% 10% 19% 19% 1	1875
	21st to end	Night	43% 6% 9% 22% 16% 4	1900
May	1st to 10th	Night	53% 6% 9% 20% 10% 1	2786
	11th to 20th	Night	53% 7% 14% 16% 9% 1	2496
	21st to end	Night	38% 9% 14% 25% 12% 2	2739
June	1st to 10th	Night	40% 6% 11% 24% 18% 1	1520
	11th to 20th	Night	39% 8% 15% 27% 11% 1	1520
	21st to end	Night	34% 8% 15% 28% 14%	1520
July	1st to 10th	Night	38% 9% 16% 20% 15% 2	2480
	11th to 20th	Night	38% 9% 15% 25% 12% 1	2472
	21st to end	Night	43% 8% 14% 16% 18% 2	2651
August	1st to 10th	Night	49% 7% 15% 18% 9% 1	2735
	11th to 20th	Night	42% 7% 13% 27% 10%	3088
	21st to end	Night	33% 6% 12% 32% 17% 1	3476
September	1st to 10th	Night	38% 5% 11% 26% 19% 1	1900
	11th to 20th	Night	34% 5% 10% 24% 25% 2	1949
	21st to end	Night	41% 5% 9% 22% 21% 1	2090
October	1st to 10th	Night	43% 5% 10% 22% 19% 1	3754
	11th to 20th	Night	29% 4 10% 28% 27% 3	3779
	21st to end	Night	31% 5% 15% 30% 18% 1	4327
November	1st to 10th	Night	35% 5% 13% 24% 21% 2	2537
	11th to 20th	Night	41% 4 10% 22% 20% 3	2600
	21st to end	Night	40% 5% 14% 28% 11% 1	2744
December	1st to 10th	Night	47% 6% 12% 22% 11% 1	2660
	11th to 20th	Night	47% 6% 14% 18% 13% 2	3288
	21st to end	Night	53% 6% 12% 21% 8%	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	32% 28% 24% 14% 2	180
	11th to 20th	Day	40% 26% 28% 4 2	180
	21st to end	Day	28% 29% 31% 8% 3 2	279
February	1st to 10th	Day	32% 29% 27% 9% 2	270
	11th to 20th	Day	36% 25% 29% 9% 1	413
	21st to end	Day	34% 25% 28% 11% 3	382
March	1st to 10th	Day	30% 24% 28% 14% 3	460
	11th to 20th	Day	29% 25% 28% 12% 3 1	460
	21st to end	Day	31% 26% 28% 9% 5% 1	506
April	1st to 10th	Day	32% 24% 26% 13% 5%	460
	11th to 20th	Day	28% 24% 26% 14% 7% 1	452
	21st to end	Day	29% 20% 31% 14% 5% 2	460
May	1st to 10th	Day	34% 21% 23% 14% 6% 2	463
	11th to 20th	Day	22% 20% 29% 19% 8% 2	487
	21st to end	Day	20% 11% 30% 25% 12% 3	529
June	1st to 10th	Day	18% 14% 32% 22% 12% 2	490
	11th to 20th	Day	19% 14% 25% 28% 13% 1	490
	21st to end	Day	16% 15% 32% 26% 10% 1	490
July	1st to 10th	Day	15% 7% 30% 26% 17% 5%	485
	11th to 20th	Day	12% 7% 28% 33% 18% 3	484
	21st to end	Day	15% 9% 35% 27% 11% 3	532
August	1st to 10th	Day	14% 7% 29% 28% 15% 6%	486
	11th to 20th	Day	14% 7% 27% 30% 16% 6%	479
	21st to end	Day	14% 11% 31% 23% 15% 7%	539
September	1st to 10th	Day	20% 12% 26% 23% 13% 7%	490
	11th to 20th	Day	13% 11% 27% 22% 16% 11%	490
	21st to end	Day	24% 10% 29% 22% 10% 5%	490
October	1st to 10th	Day	27% 11% 24% 20% 13% 5%	490
	11th to 20th	Day	20% 17% 31% 21% 10% 2	490
	21st to end	Day	28% 17% 28% 18% 8% 2	474
November	1st to 10th	Day	20% 20% 28% 21% 9% 2	395
	11th to 20th	Day	27% 21% 28% 18% 6% 1	400
	21st to end	Day	30% 24% 29% 12% 4 1	250
December	1st to 10th	Day	34% 25% 26% 10% 5%	180
	11th to 20th	Day	37% 26% 26% 8% 3	180
	21st to end	Day	30% 21% 34% 11% 4 1	198
January	1st to 10th	Night	23% 23% 35% 16% 2	760
	11th to 20th	Night	27% 21% 29% 21% 3	760
	21st to end	Night	22% 23% 35% 17% 2	836
February	1st to 10th	Night	25% 19% 34% 20% 1	760
	11th to 20th	Night	27% 24% 35% 13% 1	743
	21st to end	Night	30% 22% 30% 15% 2	628
March	1st to 10th	Night	27% 21% 31% 17% 3	760
	11th to 20th	Night	26% 23% 30% 17% 4	760
	21st to end	Night	24% 22% 33% 15% 5%	836
April	1st to 10th	Night	25% 21% 33% 17% 4	760
	11th to 20th	Night	24% 18% 33% 20% 5%	751
	21st to end	Night	25% 15% 30% 24% 5%	760
May	1st to 10th	Night	26% 13% 31% 23% 6%	542
	11th to 20th	Night	20% 11% 35% 26% 6% 1	374
	21st to end	Night	16% 7% 27% 38% 12%	411
June	1st to 10th	Night	18% 7% 24% 36% 14% 1	380
	11th to 20th	Night	14% 6% 29% 38% 13%	380
	21st to end	Night	12% 7% 26% 42% 13%	380
July	1st to 10th	Night	12% 4 24% 39% 20% 1	370
	11th to 20th	Night	11% 4 25% 43% 16% 1	368
	21st to end	Night	12% 6% 21% 44% 17% 1	416
August	1st to 10th	Night	11% 4 22% 38% 22% 3	513
	11th to 20th	Night	14% 5% 19% 36% 24% 2	723
	21st to end	Night	15% 6% 21% 35% 21% 2	836
September	1st to 10th	Night	17% 6% 26% 33% 16% 2	760
	11th to 20th	Night	15% 7% 24% 29% 21% 5%	760
	21st to end	Night	20% 8% 24% 29% 17% 2	760
October	1st to 10th	Night	25% 11% 23% 26% 14% 1	760
	11th to 20th	Night	21% 12% 28% 30% 8%	760
	21st to end	Night	26% 15% 30% 22% 8%	836
November	1st to 10th	Night	18% 17% 30% 25% 9% 1	780
	11th to 20th	Night	24% 17% 29% 22% 7% 1	800
	21st to end	Night	20% 21% 31% 22% 5% 1	800
December	1st to 10th	Night	26% 19% 30% 20% 5%	760
	11th to 20th	Night	24% 21% 32% 21% 3	760
	21st to end	Night	27% 20% 32% 20% 2	836

Page generated at 2024-11-27 17:30:51. Version ac07

Copyright © 2024 Attilla Danko.