Wheatland
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wheatland clear sky chart from 2005-11-06 to 2024-10-25.

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	6% 5% 2 5% 4 4 4 4 6% 8% 52%	101408
	Night	6% 6% 2 5% 4 4 4 3 5% 7% 53%	97639
Transparency	Day	30% 3 11% 26% 21% 10%	101150
	Night	31% 3 12% 28% 19% 7%	97487
Seeing	Day	11% 10% 28% 29% 17% 5%	15733
	Night	10% 11% 33% 35% 11% 1	25699

By Month

Percentage Cloud Cover SW (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	3 9% 3 8% 4 4 4 3 5% 6% 52%	2538
	11th to 20th	Day	4 9% 3 8% 6% 5% 5% 4 6% 8% 43%	2540
	21st to end	Day	2 6% 2 5% 3 3 3 3 4 7% 62%	3050
February	1st to 10th	Day	4 10% 4 7% 6% 3 3 4 5% 8% 45%	1710
	11th to 20th	Day	3 9% 4 7% 5% 5% 4 4 5% 7% 47%	1778
	21st to end	Day	4 7% 3 7% 5% 3 4 2 6% 6% 53%	1570
March	1st to 10th	Day	4 7% 3 7% 3 4 4 3 5% 6% 53%	3130
	11th to 20th	Day	7% 7% 3 6% 3 3 3 3 5% 6% 54%	3412
	21st to end	Day	8% 8% 3 7% 5% 5% 5% 4 6% 7% 40%	4072
April	1st to 10th	Day	9% 9% 3 5% 4 3 4 4 6% 7% 47%	2280
	11th to 20th	Day	13% 9% 3 6% 5% 5% 5% 5% 6% 7% 37%	2251
	21st to end	Day	10% 7% 2 6% 5% 4 5% 5% 5% 7% 43%	2286
May	1st to 10th	Day	17% 8% 2 6% 4 4 4 4 6% 7% 39%	4261
	11th to 20th	Day	12% 4 2 5% 4 5% 6% 4 8% 8% 42%	4388
	21st to end	Day	9% 5% 2 4 4 4 5% 5% 7% 8% 47%	4825
June	1st to 10th	Day	5% 3 1 4 4 4 5% 6% 8% 11% 49%	2660
	11th to 20th	Day	7% 3 1 4 3 4 5% 4 6% 9% 52%	2660
	21st to end	Day	4 2 1 4 3 4 5% 4 7% 8% 57%	2660
July	1st to 10th	Day	4 2 1 3 3 3 4 4 7% 7% 60%	4430
	11th to 20th	Day	2 2 1 3 4 4 5% 5% 9% 10% 55%	4430
	21st to end	Day	3 2 1 4 3 4 4 4 7% 8% 59%	4802
August	1st to 10th	Day	7% 3 1 4 4 4 5% 5% 7% 9% 51%	4202
	11th to 20th	Day	3 2 1 5% 4 4 6% 4 6% 7% 56%	3815
	21st to end	Day	3 3 1 4 4 4 4 4 6% 6% 62%	4180
September	1st to 10th	Day	6% 3 1 3 3 3 4 3 5% 6% 63%	2280
	11th to 20th	Day	7% 3 1 3 3 3 3 3 5% 7% 64%	2257
	21st to end	Day	6% 3 2 3 3 3 2 3 4 7% 65%	2090
October	1st to 10th	Day	8% 5% 2 4 3 4 3 2 4 6% 59%	1909
	11th to 20th	Day	8% 5% 2 4 4 3 4 3 4 6% 59%	1900
	21st to end	Day	6% 6% 2 5% 2 2 3 3 5% 8% 58%	1903
November	1st to 10th	Day	4 6% 2 5% 4 4 3 4 6% 8% 56%	1673
	11th to 20th	Day	4 6% 3 4 3 3 3 2 6% 8% 60%	1706
	21st to end	Day	3 8% 3 6% 3 3 3 3 7% 7% 54%	1520
December	1st to 10th	Day	3 9% 3 5% 4 4 4 4 5% 8% 50%	1520
	11th to 20th	Day	3 7% 3 5% 3 3 3 3 5% 9% 56%	1926
	21st to end	Day	7% 9% 3 6% 4 3 4 3 5% 7% 50%	2794
January	1st to 10th	Night	3 8% 4 7% 4 4 4 3 5% 7% 51%	4417
	11th to 20th	Night	2 8% 4 6% 5% 5% 4 4 5% 7% 49%	4430
	21st to end	Night	3 7% 2 6% 3 3 3 3 4 6% 58%	4646
February	1st to 10th	Night	4 9% 3 8% 4 4 5% 3 6% 8% 46%	2470
	11th to 20th	Night	4 10% 3 7% 5% 4 5% 3 6% 6% 47%	2287
	21st to end	Night	3 8% 3 7% 4 3 4 3 5% 7% 51%	1884
March	1st to 10th	Night	4 9% 2 5% 3 3 4 3 5% 9% 52%	3734
	11th to 20th	Night	7% 10% 2 6% 3 3 3 3 4 6% 53%	3562
	21st to end	Night	9% 11% 3 8% 5% 4 4 3 5% 6% 41%	3573
April	1st to 10th	Night	11% 7% 3 5% 3 3 4 4 5% 7% 48%	1900
	11th to 20th	Night	12% 7% 2 6% 5% 4 5% 4 5% 6% 45%	1877
	21st to end	Night	14% 8% 2 6% 4 3 4 3 5% 7% 45%	1891
May	1st to 10th	Night	14% 9% 2 7% 3 4 3 3 5% 6% 45%	2706
	11th to 20th	Night	11% 4 1 5% 3 3 4 3 6% 7% 52%	2517
	21st to end	Night	11% 4 1 4 4 4 4 4 7% 8% 49%	2762
June	1st to 10th	Night	5% 4 1 4 4 3 4 4 7% 9% 55%	1520
	11th to 20th	Night	8% 3 1 3 3 3 4 4 6% 9% 56%	1520
	21st to end	Night	3 2 1 4 3 3 4 4 5% 8% 63%	1520
July	1st to 10th	Night	6% 2 1 4 3 4 5% 5% 7% 7% 56%	2540
	11th to 20th	Night	3 2 1 3 3 4 5% 6% 6% 9% 59%	2540
	21st to end	Night	4 3 1 5% 4 5% 5% 4 7% 9% 55%	2761
August	1st to 10th	Night	11% 3 1 4 3 4 5% 4 7% 9% 49%	2734
	11th to 20th	Night	3 3 1 6% 5% 5% 6% 5% 7% 8% 52%	3022
	21st to end	Night	3 3 1 4 3 3 4 3 6% 9% 61%	3487
September	1st to 10th	Night	7% 4 1 3 3 2 3 3 4 6% 64%	1900
	11th to 20th	Night	7% 3 1 3 3 3 3 3 5% 6% 63%	1922
	21st to end	Night	8% 3 1 3 3 2 3 2 4 5% 65%	2090
October	1st to 10th	Night	9% 5% 1 3 2 3 3 3 4 6% 59%	2269
	11th to 20th	Night	8% 6% 2 4 3 3 3 2 4 5% 60%	2280
	21st to end	Night	8% 7% 2 4 3 3 3 3 5% 5% 58%	2539
November	1st to 10th	Night	6% 5% 2 5% 3 3 3 3 5% 8% 57%	2405
	11th to 20th	Night	4 7% 2 5% 4 4 4 4 6% 7% 53%	2470
	21st to end	Night	5% 8% 2 5% 3 3 4 3 5% 7% 56%	2660
December	1st to 10th	Night	4 8% 3 6% 4 4 4 3 5% 7% 51%	2660
	11th to 20th	Night	4 8% 2 4 4 3 4 3 6% 7% 57%	3271
	21st to end	Night	8% 10% 3 6% 4 3 3 3 5% 7% 47%	4873

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	35% 2 13% 30% 20% 1	2539
	11th to 20th	Day	40% 3 19% 22% 14% 2	2540
	21st to end	Day	24% 2 19% 35% 16% 4	3050
February	1st to 10th	Day	38% 3 16% 27% 14% 2	1710
	11th to 20th	Day	36% 4 10% 29% 16% 5%	1787
	21st to end	Day	31% 3 16% 26% 18% 5%	1570
March	1st to 10th	Day	32% 2 6% 29% 27% 4	3130
	11th to 20th	Day	32% 2 16% 34% 13% 2	3412
	21st to end	Day	42% 3 12% 32% 10% 1	4072
April	1st to 10th	Day	36% 5% 14% 24% 17% 5%	2280
	11th to 20th	Day	45% 5% 9% 21% 17% 4	2254
	21st to end	Day	39% 4 10% 28% 18% 2	2286
May	1st to 10th	Day	45% 3 9% 24% 14% 6%	4261
	11th to 20th	Day	38% 3 11% 30% 14% 5%	4392
	21st to end	Day	32% 3 13% 30% 17% 5%	4825
June	1st to 10th	Day	26% 4 16% 29% 19% 6%	2660
	11th to 20th	Day	28% 4 11% 23% 20% 14%	2660
	21st to end	Day	23% 4 8% 24% 27% 15%	2660
July	1st to 10th	Day	20% 5% 6% 20% 28% 21%	4361
	11th to 20th	Day	20% 4 7% 24% 24% 20%	4355
	21st to end	Day	21% 3 7% 19% 25% 25%	4651
August	1st to 10th	Day	27% 3 10% 25% 21% 13%	4187
	11th to 20th	Day	26% 3 8% 21% 24% 18%	3853
	21st to end	Day	21% 3 7% 18% 27% 24%	4179
September	1st to 10th	Day	22% 3 5% 19% 30% 21%	2280
	11th to 20th	Day	21% 2 5% 23% 30% 18%	2257
	21st to end	Day	21% 3 6% 27% 33% 11%	2090
October	1st to 10th	Day	28% 3 8% 27% 24% 10%	1909
	11th to 20th	Day	28% 2 9% 29% 24% 9%	1900
	21st to end	Day	25% 3 11% 31% 23% 6%	1903
November	1st to 10th	Day	27% 2 12% 27% 25% 7%	1673
	11th to 20th	Day	24% 2 12% 34% 23% 5%	1706
	21st to end	Day	28% 3 11% 29% 25% 4	1520
December	1st to 10th	Day	31% 4 16% 28% 18% 3	1520
	11th to 20th	Day	27% 2 12% 39% 18% 1	1924
	21st to end	Day	36% 2 11% 33% 15% 3	2794
January	1st to 10th	Night	34% 2 11% 35% 15% 2	4417
	11th to 20th	Night	36% 5% 18% 20% 17% 4	4430
	21st to end	Night	29% 2 22% 33% 12% 2	4646
February	1st to 10th	Night	36% 4 16% 28% 14% 2	2470
	11th to 20th	Night	37% 4 12% 28% 16% 4	2288
	21st to end	Night	32% 3 12% 28% 22% 4	1884
March	1st to 10th	Night	30% 2 7% 34% 23% 4	3734
	11th to 20th	Night	34% 2 14% 30% 17% 3	3562
	21st to end	Night	45% 1 17% 26% 9% 1	3573
April	1st to 10th	Night	35% 4 12% 26% 16% 5%	1900
	11th to 20th	Night	40% 4 11% 25% 17% 4	1877
	21st to end	Night	40% 2 9% 27% 19% 2	1891
May	1st to 10th	Night	41% 2 9% 26% 19% 3	2706
	11th to 20th	Night	32% 3 13% 35% 13% 5%	2518
	21st to end	Night	32% 4 15% 27% 18% 4	2762
June	1st to 10th	Night	24% 4 22% 27% 17% 5%	1520
	11th to 20th	Night	25% 3 14% 26% 22% 11%	1520
	21st to end	Night	20% 4 10% 28% 25% 13%	1520
July	1st to 10th	Night	25% 4 10% 22% 21% 18%	2500
	11th to 20th	Night	21% 4 12% 26% 25% 12%	2492
	21st to end	Night	25% 3 11% 21% 25% 15%	2674
August	1st to 10th	Night	32% 3 13% 25% 19% 9%	2726
	11th to 20th	Night	29% 3 12% 24% 18% 14%	3050
	21st to end	Night	21% 3 10% 20% 26% 20%	3487
September	1st to 10th	Night	23% 2 5% 22% 29% 18%	1900
	11th to 20th	Night	22% 2 7% 26% 26% 17%	1922
	21st to end	Night	22% 2 6% 26% 28% 15%	2090
October	1st to 10th	Night	27% 3 11% 24% 25% 11%	2269
	11th to 20th	Night	28% 2 10% 28% 23% 10%	2280
	21st to end	Night	29% 2 11% 29% 20% 9%	2539
November	1st to 10th	Night	27% 3 13% 26% 26% 6%	2405
	11th to 20th	Night	29% 3 10% 31% 21% 6%	2470
	21st to end	Night	29% 3 10% 31% 23% 6%	2660
December	1st to 10th	Night	33% 3 15% 28% 19% 4	2660
	11th to 20th	Night	28% 3 13% 38% 17% 1	3272
	21st to end	Night	38% 3 10% 32% 15% 3	4873

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	13% 16% 33% 27% 8% 3	270
	11th to 20th	Day	15% 21% 35% 23% 5% 1	270
	21st to end	Day	7% 22% 46% 17% 7%	297
February	1st to 10th	Day	9% 25% 44% 18% 3 1	270
	11th to 20th	Day	15% 27% 30% 24% 4	270
	21st to end	Day	19% 24% 30% 21% 5%	225
March	1st to 10th	Day	9% 23% 32% 33% 4	270
	11th to 20th	Day	17% 15% 33% 25% 9% 1	408
	21st to end	Day	18% 16% 34% 24% 7% 2	506
April	1st to 10th	Day	19% 18% 36% 21% 6%	460
	11th to 20th	Day	23% 16% 36% 18% 6% 2	452
	21st to end	Day	17% 11% 32% 25% 12% 3	466
May	1st to 10th	Day	19% 11% 28% 25% 14% 3	653
	11th to 20th	Day	21% 7% 19% 29% 21% 4	675
	21st to end	Day	13% 8% 23% 32% 18% 5%	734
June	1st to 10th	Day	5% 6% 23% 30% 25% 10%	680
	11th to 20th	Day	10% 8% 27% 35% 18% 3	680
	21st to end	Day	6% 3 27% 35% 24% 5%	680
July	1st to 10th	Day	6% 2 16% 37% 29% 10%	671
	11th to 20th	Day	4 3 18% 35% 34% 6%	668
	21st to end	Day	6% 2 15% 34% 34% 8%	739
August	1st to 10th	Day	6% 3 21% 34% 28% 9%	558
	11th to 20th	Day	4 3 24% 31% 27% 12%	477
	21st to end	Day	4 5% 23% 34% 24% 10%	539
September	1st to 10th	Day	7% 5% 22% 34% 23% 9%	490
	11th to 20th	Day	7% 6% 26% 31% 22% 7%	467
	21st to end	Day	8% 7% 23% 33% 17% 13%	300
October	1st to 10th	Day	10% 8% 20% 30% 20% 12%	300
	11th to 20th	Day	12% 13% 25% 28% 14% 8%	300
	21st to end	Day	13% 14% 33% 27% 10% 3	311
November	1st to 10th	Day	10% 10% 35% 33% 10% 3	270
	11th to 20th	Day	14% 17% 35% 26% 8% 1	270
	21st to end	Day	10% 16% 40% 26% 7%	270
December	1st to 10th	Day	10% 20% 43% 19% 8%	270
	11th to 20th	Day	9% 21% 48% 19% 2	270
	21st to end	Day	14% 23% 35% 22% 5% 1	297
January	1st to 10th	Night	10% 20% 40% 22% 7% 1	950
	11th to 20th	Night	9% 24% 44% 20% 4	950
	21st to end	Night	10% 17% 45% 24% 4	909
February	1st to 10th	Night	9% 17% 46% 24% 4	760
	11th to 20th	Night	12% 15% 40% 28% 5%	744
	21st to end	Night	11% 19% 41% 24% 4	628
March	1st to 10th	Night	11% 16% 40% 29% 4	760
	11th to 20th	Night	13% 11% 32% 36% 8%	760
	21st to end	Night	15% 11% 35% 33% 6% 1	684
April	1st to 10th	Night	15% 12% 36% 33% 4	570
	11th to 20th	Night	15% 9% 36% 33% 7%	563
	21st to end	Night	17% 7% 29% 35% 11% 1	570
May	1st to 10th	Night	20% 7% 24% 34% 14% 1	570
	11th to 20th	Night	18% 4 19% 40% 17% 2	561
	21st to end	Night	11% 4 28% 40% 17%	617
June	1st to 10th	Night	7% 4 25% 42% 21% 1	570
	11th to 20th	Night	9% 3 31% 48% 8% 1	570
	21st to end	Night	4 2 28% 49% 16% 1	570
July	1st to 10th	Night	6% 3 13% 50% 26% 1	555
	11th to 20th	Night	4 2 19% 52% 22% 1	552
	21st to end	Night	4 1 14% 53% 27% 1	624
August	1st to 10th	Night	7% 1 12% 54% 24% 1	567
	11th to 20th	Night	4 1 18% 54% 23% 1	564
	21st to end	Night	4 2 18% 50% 25% 1	627
September	1st to 10th	Night	9% 2 18% 49% 20% 2	570
	11th to 20th	Night	8% 4 22% 45% 19% 2	570
	21st to end	Night	10% 3 26% 45% 16% 1	570
October	1st to 10th	Night	13% 5% 27% 36% 17% 2	749
	11th to 20th	Night	12% 6% 31% 40% 11% 1	760
	21st to end	Night	13% 9% 34% 35% 8% 1	915
November	1st to 10th	Night	11% 7% 40% 34% 7% 1	925
	11th to 20th	Night	8% 17% 43% 28% 4	950
	21st to end	Night	9% 12% 41% 32% 6%	950
December	1st to 10th	Night	11% 22% 41% 23% 4	950
	11th to 20th	Night	10% 18% 44% 23% 4	950
	21st to end	Night	13% 21% 41% 21% 4	1045

Page generated at 2024-10-22 18:21:01. Version ac07

Copyright © 2024 Attilla Danko.