Bucyrus
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bucyrus clear sky chart from 2005-11-06 to 2025-02-21.

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	15% 11% 4 9% 5% 5% 5% 4 5% 7% 31%	109894
	Night	15% 12% 4 9% 5% 4 4 3 5% 6% 32%	108718
Transparency	Day	51% 6% 11% 19% 12% 1	113566
	Night	51% 5% 11% 20% 12% 2	113185
Seeing	Day	19% 11% 27% 23% 14% 6%	15693
	Night	20% 9% 28% 29% 13% 1	25299

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	14% 18% 9% 22% 7% 5% 3 3 4 5% 10%	4053
	11th to 20th	Day	13% 21% 6% 16% 8% 5% 7% 3 3 3 15%	4060
	21st to end	Day	21% 17% 9% 13% 7% 6% 4 3 3 3 12%	4466
February	1st to 10th	Day	17% 16% 6% 14% 8% 5% 3 3 4 5% 19%	1800
	11th to 20th	Day	14% 13% 6% 15% 7% 4 5% 3 4 6% 22%	1908
	21st to end	Day	17% 15% 4 10% 5% 5% 4 3 5% 5% 26%	1570
March	1st to 10th	Day	21% 17% 7% 9% 6% 4 3 3 4 5% 21%	3245
	11th to 20th	Day	12% 13% 5% 9% 6% 5% 4 3 4 6% 33%	3480
	21st to end	Day	21% 12% 5% 10% 5% 4 4 3 4 6% 26%	3815
April	1st to 10th	Day	13% 14% 4 8% 6% 4 5% 4 6% 6% 30%	2153
	11th to 20th	Day	17% 11% 3 7% 6% 4 4 4 5% 6% 35%	2404
	21st to end	Day	19% 9% 3 7% 5% 4 4 3 6% 7% 32%	2470
May	1st to 10th	Day	19% 10% 3 7% 5% 5% 5% 4 6% 6% 29%	4082
	11th to 20th	Day	19% 8% 3 7% 5% 4 5% 4 5% 7% 33%	4081
	21st to end	Day	11% 6% 2 7% 5% 5% 6% 5% 7% 9% 38%	4476
June	1st to 10th	Day	13% 7% 3 6% 5% 5% 5% 5% 7% 8% 37%	2470
	11th to 20th	Day	11% 7% 3 6% 6% 5% 5% 5% 6% 8% 38%	2618
	21st to end	Day	11% 5% 2 6% 6% 5% 5% 5% 8% 10% 37%	2660
July	1st to 10th	Day	10% 7% 3 7% 5% 5% 5% 4 7% 10% 36%	4440
	11th to 20th	Day	9% 5% 2 6% 5% 5% 5% 5% 7% 10% 43%	4194
	21st to end	Day	9% 6% 2 7% 5% 5% 6% 5% 8% 8% 39%	4466
August	1st to 10th	Day	10% 6% 3 7% 4 5% 5% 5% 7% 10% 38%	4104
	11th to 20th	Day	10% 5% 2 6% 4 5% 5% 5% 8% 11% 39%	4044
	21st to end	Day	8% 5% 3 6% 5% 5% 5% 4 7% 10% 43%	4477
September	1st to 10th	Day	12% 6% 2 6% 4 4 5% 3 4 7% 46%	2109
	11th to 20th	Day	9% 6% 2 7% 4 4 4 3 5% 8% 46%	2090
	21st to end	Day	18% 8% 2 6% 4 3 3 3 4 6% 42%	2090
October	1st to 10th	Day	13% 8% 3 6% 4 5% 4 3 5% 7% 42%	2033
	11th to 20th	Day	15% 9% 3 8% 4 3 4 4 6% 7% 37%	1900
	21st to end	Day	20% 11% 3 6% 5% 5% 4 3 5% 8% 29%	2005
November	1st to 10th	Day	12% 9% 3 6% 5% 4 5% 2 5% 6% 43%	1762
	11th to 20th	Day	18% 14% 4 7% 4 4 4 3 5% 6% 31%	1800
	21st to end	Day	18% 17% 5% 9% 4 5% 3 2 4 6% 26%	1800
December	1st to 10th	Day	16% 16% 7% 15% 6% 4 3 3 4 5% 20%	2930
	11th to 20th	Day	20% 19% 8% 11% 5% 4 4 3 4 5% 19%	3373
	21st to end	Day	24% 23% 7% 12% 5% 4 3 3 3 3 12%	4466
January	1st to 10th	Night	15% 20% 8% 17% 6% 4 3 3 4 4 15%	5889
	11th to 20th	Night	11% 19% 10% 17% 8% 7% 5% 4 3 3 12%	5900
	21st to end	Night	21% 17% 6% 12% 5% 4 4 2 4 4 20%	6490
February	1st to 10th	Night	19% 14% 6% 12% 6% 5% 5% 4 4 5% 21%	2600
	11th to 20th	Night	16% 15% 4 11% 7% 5% 3 3 5% 5% 24%	2373
	21st to end	Night	20% 15% 4 11% 6% 4 4 3 3 4 26%	1885
March	1st to 10th	Night	19% 15% 4 7% 5% 4 3 3 4 5% 32%	3606
	11th to 20th	Night	13% 9% 3 6% 5% 4 4 4 5% 7% 40%	3480
	21st to end	Night	18% 10% 3 8% 5% 4 4 3 5% 5% 36%	3817
April	1st to 10th	Night	15% 12% 3 8% 5% 4 5% 4 5% 6% 33%	2043
	11th to 20th	Night	17% 8% 3 7% 4 4 4 4 6% 7% 36%	1723
	21st to end	Night	16% 9% 3 7% 5% 5% 5% 4 5% 7% 36%	1710
May	1st to 10th	Night	22% 9% 4 7% 5% 5% 5% 4 5% 6% 27%	2813
	11th to 20th	Night	18% 7% 2 7% 4 4 4 4 5% 8% 38%	2812
	21st to end	Night	10% 6% 2 5% 4 4 5% 4 8% 9% 45%	3079
June	1st to 10th	Night	9% 7% 2 6% 4 4 5% 4 5% 7% 45%	1710
	11th to 20th	Night	7% 6% 2 5% 4 5% 5% 5% 7% 10% 44%	1555
	21st to end	Night	9% 4 2 5% 5% 4 4 5% 7% 10% 44%	1520
July	1st to 10th	Night	10% 5% 2 5% 5% 4 4 4 7% 8% 47%	2530
	11th to 20th	Night	8% 3 2 5% 3 4 4 5% 6% 9% 51%	2764
	21st to end	Night	7% 6% 2 6% 4 6% 5% 4 6% 9% 44%	3087
August	1st to 10th	Night	10% 7% 3 8% 4 5% 5% 5% 8% 9% 37%	2825
	11th to 20th	Night	10% 8% 2 7% 4 4 4 3 6% 8% 43%	2785
	21st to end	Night	6% 4 2 5% 4 5% 6% 5% 6% 8% 50%	3176
September	1st to 10th	Night	10% 6% 2 5% 4 3 4 3 5% 7% 51%	2052
	11th to 20th	Night	10% 5% 2 4 3 4 3 3 5% 7% 54%	2090
	21st to end	Night	16% 7% 2 5% 3 4 4 3 5% 6% 45%	2090
October	1st to 10th	Night	11% 6% 2 5% 4 5% 4 3 5% 7% 49%	2147
	11th to 20th	Night	17% 8% 3 7% 4 4 4 3 4 6% 39%	2280
	21st to end	Night	22% 8% 3 6% 4 4 5% 3 4 6% 35%	2589
November	1st to 10th	Night	13% 8% 3 6% 4 4 4 3 5% 6% 44%	2536
	11th to 20th	Night	16% 14% 4 8% 4 4 3 3 4 7% 33%	2600
	21st to end	Night	19% 15% 4 8% 5% 4 4 4 5% 6% 26%	2600
December	1st to 10th	Night	15% 13% 5% 13% 7% 5% 4 3 5% 5% 23%	4250
	11th to 20th	Night	19% 19% 7% 11% 5% 3 3 3 4 5% 20%	4822
	21st to end	Night	23% 21% 7% 11% 4 3 4 3 4 6% 14%	6490

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	77% 5% 7% 8% 2	4054
	11th to 20th	Day	76% 3 7% 6% 7%	4060
	21st to end	Day	79% 3 5% 8% 5%	4466
February	1st to 10th	Day	68% 5% 8% 13% 6%	1800
	11th to 20th	Day	65% 5% 7% 16% 7% 1	1918
	21st to end	Day	60% 5% 12% 14% 6% 2	1570
March	1st to 10th	Day	65% 5% 8% 18% 4	3245
	11th to 20th	Day	52% 5% 12% 22% 8% 1	3480
	21st to end	Day	59% 4 13% 16% 7%	3815
April	1st to 10th	Day	53% 6% 13% 17% 11% 1	2153
	11th to 20th	Day	49% 6% 12% 18% 13% 2	2404
	21st to end	Day	51% 5% 11% 20% 11% 2	2470
May	1st to 10th	Day	53% 7% 11% 20% 8% 1	4120
	11th to 20th	Day	48% 8% 12% 23% 9% 1	4085
	21st to end	Day	39% 9% 13% 19% 16% 4	4489
June	1st to 10th	Day	43% 7% 11% 25% 13% 1	2470
	11th to 20th	Day	41% 8% 13% 22% 15% 1	2618
	21st to end	Day	39% 8% 14% 20% 15% 3	2660
July	1st to 10th	Day	41% 8% 12% 21% 17% 2	4371
	11th to 20th	Day	33% 8% 14% 24% 19% 2	4122
	21st to end	Day	39% 8% 14% 17% 19% 3	4324
August	1st to 10th	Day	39% 8% 15% 24% 14% 1	4091
	11th to 20th	Day	36% 8% 13% 29% 13% 1	4083
	21st to end	Day	36% 7% 14% 28% 13% 3	4476
September	1st to 10th	Day	37% 7% 12% 22% 18% 4	2109
	11th to 20th	Day	37% 5% 11% 25% 19% 2	2090
	21st to end	Day	44% 4 11% 21% 19% 1	2090
October	1st to 10th	Day	29% 5% 12% 31% 22% 1	3384
	11th to 20th	Day	38% 5% 10% 24% 21% 1	3140
	21st to end	Day	43% 4 12% 22% 19% 1	3281
November	1st to 10th	Day	43% 4 12% 24% 15% 2	1762
	11th to 20th	Day	55% 4 10% 19% 10% 2	1800
	21st to end	Day	61% 4 10% 17% 8% 1	1800
December	1st to 10th	Day	67% 5% 13% 12% 2	2930
	11th to 20th	Day	69% 3 10% 14% 4	3370
	21st to end	Day	79% 3 7% 8% 4	4466
January	1st to 10th	Night	74% 4 6% 13% 3	5889
	11th to 20th	Night	78% 3 7% 7% 5%	5900
	21st to end	Night	69% 3 11% 10% 6% 1	6490
February	1st to 10th	Night	66% 4 9% 14% 7% 1	2600
	11th to 20th	Night	62% 3 10% 16% 8% 1	2374
	21st to end	Night	63% 4 8% 15% 8% 1	1885
March	1st to 10th	Night	56% 4 11% 20% 8% 1	3606
	11th to 20th	Night	42% 6% 14% 24% 12% 2	3480
	21st to end	Night	49% 5% 11% 25% 9% 1	3817
April	1st to 10th	Night	50% 6% 12% 16% 14% 2	2043
	11th to 20th	Night	46% 5% 12% 17% 17% 2	1723
	21st to end	Night	46% 6% 10% 21% 14% 2	1710
May	1st to 10th	Night	55% 7% 10% 17% 9% 2	2840
	11th to 20th	Night	44% 8% 12% 23% 13% 1	2813
	21st to end	Night	32% 8% 13% 28% 17% 2	3087
June	1st to 10th	Night	38% 6% 12% 24% 17% 3	1710
	11th to 20th	Night	33% 8% 14% 25% 16% 3	1555
	21st to end	Night	34% 8% 14% 25% 15% 4	1520
July	1st to 10th	Night	35% 7% 10% 26% 16% 6%	2490
	11th to 20th	Night	28% 7% 14% 31% 19% 1	2713
	21st to end	Night	35% 6% 15% 20% 21% 3	2988
August	1st to 10th	Night	40% 9% 13% 22% 15% 1	2814
	11th to 20th	Night	38% 6% 10% 27% 17% 1	2812
	21st to end	Night	31% 7% 14% 29% 16% 3	3176
September	1st to 10th	Night	34% 6% 11% 25% 18% 5%	2052
	11th to 20th	Night	30% 5% 10% 26% 25% 3	2090
	21st to end	Night	40% 6% 10% 22% 20% 2	2090
October	1st to 10th	Night	26% 4 8% 30% 31% 1	3576
	11th to 20th	Night	37% 4 10% 26% 21% 3	3779
	21st to end	Night	38% 3 9% 28% 18% 3	4263
November	1st to 10th	Night	42% 4 12% 23% 17% 2	2536
	11th to 20th	Night	52% 4 10% 21% 12% 3	2600
	21st to end	Night	59% 4 12% 17% 7% 1	2600
December	1st to 10th	Night	63% 5% 10% 16% 6% 1	4250
	11th to 20th	Night	68% 3 12% 12% 4	4824
	21st to end	Night	73% 4 10% 10% 4	6490

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	25% 19% 35% 16% 5% 1	300
	11th to 20th	Day	22% 20% 43% 10% 4 1	300
	21st to end	Day	25% 22% 30% 19% 3	330
February	1st to 10th	Day	30% 14% 39% 14% 2 1	300
	11th to 20th	Day	26% 19% 32% 20% 2	300
	21st to end	Day	24% 24% 38% 13% 1	225
March	1st to 10th	Day	23% 18% 35% 19% 5%	343
	11th to 20th	Day	23% 19% 35% 18% 5% 1	460
	21st to end	Day	30% 14% 30% 21% 4 1	506
April	1st to 10th	Day	20% 15% 33% 21% 8% 2	460
	11th to 20th	Day	20% 20% 29% 18% 9% 4	452
	21st to end	Day	24% 14% 32% 20% 8% 2	460
May	1st to 10th	Day	25% 11% 29% 23% 9% 3	463
	11th to 20th	Day	23% 7% 28% 23% 13% 6%	487
	21st to end	Day	12% 7% 24% 26% 21% 10%	529
June	1st to 10th	Day	14% 6% 26% 32% 17% 6%	490
	11th to 20th	Day	14% 7% 25% 28% 20% 5%	638
	21st to end	Day	14% 7% 27% 27% 19% 6%	680
July	1st to 10th	Day	13% 3 21% 27% 21% 15%	671
	11th to 20th	Day	11% 4 21% 28% 24% 12%	529
	21st to end	Day	11% 3 18% 28% 28% 12%	532
August	1st to 10th	Day	11% 5% 16% 25% 28% 16%	486
	11th to 20th	Day	12% 3 20% 29% 25% 11%	479
	21st to end	Day	11% 4 17% 27% 27% 15%	539
September	1st to 10th	Day	14% 3 19% 26% 26% 11%	490
	11th to 20th	Day	11% 3 14% 23% 32% 18%	490
	21st to end	Day	21% 8% 21% 24% 17% 9%	490
October	1st to 10th	Day	13% 8% 26% 25% 20% 9%	490
	11th to 20th	Day	15% 17% 31% 23% 11% 4	490
	21st to end	Day	25% 14% 34% 19% 6% 1	454
November	1st to 10th	Day	15% 16% 35% 21% 11% 2	300
	11th to 20th	Day	27% 18% 30% 17% 8% 1	300
	21st to end	Day	28% 19% 34% 18% 1	300
December	1st to 10th	Day	23% 20% 35% 16% 5% 1	300
	11th to 20th	Day	25% 20% 36% 17% 3	300
	21st to end	Day	32% 17% 33% 16% 2	330
January	1st to 10th	Night	25% 16% 37% 18% 4	800
	11th to 20th	Night	28% 16% 37% 16% 3 1	800
	21st to end	Night	24% 15% 36% 21% 3	880
February	1st to 10th	Night	24% 14% 38% 21% 3	800
	11th to 20th	Night	25% 14% 34% 25% 3	783
	21st to end	Night	28% 14% 39% 17% 3	629
March	1st to 10th	Night	23% 13% 34% 23% 7%	760
	11th to 20th	Night	20% 14% 35% 25% 6% 1	760
	21st to end	Night	24% 10% 32% 26% 7%	836
April	1st to 10th	Night	21% 12% 35% 26% 5% 1	713
	11th to 20th	Night	22% 10% 35% 23% 9% 1	563
	21st to end	Night	21% 8% 38% 24% 8% 1	570
May	1st to 10th	Night	23% 7% 30% 31% 9% 1	570
	11th to 20th	Night	22% 4 26% 32% 13% 2	561
	21st to end	Night	11% 3 23% 39% 22% 2	617
June	1st to 10th	Night	11% 3 25% 42% 18% 1	570
	11th to 20th	Night	12% 4 19% 44% 20% 1	570
	21st to end	Night	11% 4 22% 41% 21% 1	570
July	1st to 10th	Night	10% 2 14% 42% 28% 3	555
	11th to 20th	Night	9% 2 17% 41% 27% 4	552
	21st to end	Night	9% 2 13% 43% 31% 2	624
August	1st to 10th	Night	8% 2 12% 46% 28% 4	567
	11th to 20th	Night	12% 3 12% 40% 29% 5%	564
	21st to end	Night	8% 2 12% 38% 35% 5%	627
September	1st to 10th	Night	12% 4 15% 37% 27% 5%	722
	11th to 20th	Night	12% 3 13% 36% 30% 5%	760
	21st to end	Night	18% 6% 21% 32% 20% 3	760
October	1st to 10th	Night	13% 6% 25% 34% 19% 2	760
	11th to 20th	Night	21% 10% 30% 27% 11% 1	760
	21st to end	Night	26% 11% 30% 25% 8%	836
November	1st to 10th	Night	19% 8% 33% 27% 12% 1	780
	11th to 20th	Night	23% 14% 32% 24% 6% 2	800
	21st to end	Night	27% 11% 34% 23% 6% 1	800
December	1st to 10th	Night	27% 15% 32% 21% 5%	800
	11th to 20th	Night	26% 13% 35% 21% 4	800
	21st to end	Night	29% 15% 32% 21% 3	880

Page generated at 2025-02-18 03:26:32. Version ac07

Copyright © 2025 Attilla Danko.