Ottawa (KS)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ottawa (KS) 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	11% 7% 3 6% 4 4 4 3 5% 7% 46%	100864
	Night	11% 7% 2 6% 4 4 4 3 5% 6% 49%	98214
Transparency	Day	36% 6% 12% 26% 18% 3	104514
	Night	34% 6% 11% 26% 20% 4	102691
Seeing	Day	14% 9% 28% 28% 17% 4	15641
	Night	14% 9% 32% 33% 12% 1	25463

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% 10% 3 9% 4 4 4 3 5% 6% 37%	2847
	11th to 20th	Day	10% 10% 4 9% 5% 7% 5% 3 4 5% 39%	2850
	21st to end	Day	13% 15% 6% 8% 4 3 3 2 4 5% 37%	3135
February	1st to 10th	Day	14% 11% 3 6% 4 5% 3 2 3 6% 42%	1710
	11th to 20th	Day	12% 8% 3 8% 5% 5% 4 3 4 6% 42%	1692
	21st to end	Day	11% 8% 3 7% 3 4 4 4 5% 6% 45%	1613
March	1st to 10th	Day	12% 9% 2 6% 3 3 3 3 4 6% 49%	3436
	11th to 20th	Day	11% 6% 2 3 3 3 3 3 5% 6% 55%	3480
	21st to end	Day	14% 11% 5% 7% 4 4 4 3 5% 6% 38%	3814
April	1st to 10th	Day	14% 7% 2 6% 4 3 4 3 4 6% 47%	2161
	11th to 20th	Day	15% 7% 3 6% 4 4 4 4 5% 6% 42%	2254
	21st to end	Day	19% 8% 2 7% 5% 4 4 4 4 6% 37%	2450
May	1st to 10th	Day	16% 9% 3 7% 5% 4 4 3 5% 7% 38%	4082
	11th to 20th	Day	15% 7% 2 7% 4 4 4 4 6% 8% 40%	4082
	21st to end	Day	13% 6% 2 6% 5% 4 4 4 5% 8% 43%	4477
June	1st to 10th	Day	6% 3 2 4 4 5% 4 5% 8% 11% 47%	2527
	11th to 20th	Day	7% 5% 2 5% 4 4 4 3 7% 9% 48%	2636
	21st to end	Day	7% 4 1 4 4 4 4 4 6% 9% 53%	2470
July	1st to 10th	Day	11% 6% 2 6% 4 4 5% 4 7% 8% 42%	4120
	11th to 20th	Day	5% 3 2 5% 3 4 4 4 7% 10% 54%	4120
	21st to end	Day	6% 4 2 5% 4 5% 6% 5% 9% 11% 43%	4465
August	1st to 10th	Day	6% 4 2 5% 4 4 4 4 5% 8% 54%	4104
	11th to 20th	Day	11% 6% 2 6% 4 4 4 4 5% 8% 47%	4041
	21st to end	Day	6% 4 1 5% 3 3 4 4 6% 8% 56%	4313
September	1st to 10th	Day	13% 5% 2 5% 3 3 2 3 5% 7% 54%	2242
	11th to 20th	Day	9% 5% 2 5% 4 3 5% 4 5% 8% 50%	2090
	21st to end	Day	9% 4 2 5% 4 3 4 4 5% 6% 54%	2090
October	1st to 10th	Day	11% 6% 2 5% 3 4 3 3 5% 6% 53%	1916
	11th to 20th	Day	11% 6% 1 4 2 3 2 2 4 5% 59%	1900
	21st to end	Day	15% 6% 2 6% 3 4 3 2 3 5% 51%	2090
November	1st to 10th	Day	9% 6% 1 5% 3 2 4 3 4 6% 56%	1861
	11th to 20th	Day	13% 6% 2 4 3 3 3 3 4 7% 53%	1710
	21st to end	Day	15% 8% 3 5% 4 2 2 2 3 5% 51%	1546
December	1st to 10th	Day	10% 9% 3 5% 4 4 3 3 4 8% 49%	1520
	11th to 20th	Day	12% 10% 3 7% 5% 4 4 3 4 5% 42%	1918
	21st to end	Day	16% 15% 7% 9% 4 5% 4 3 5% 5% 27%	3102
January	1st to 10th	Night	9% 9% 3 13% 5% 4 3 3 3 5% 42%	4108
	11th to 20th	Night	10% 8% 3 8% 6% 7% 6% 3 5% 5% 39%	4120
	21st to end	Night	16% 12% 4 8% 4 3 3 3 4 5% 38%	4532
February	1st to 10th	Night	11% 12% 3 6% 5% 4 4 4 5% 5% 41%	2470
	11th to 20th	Night	12% 9% 3 6% 4 3 3 3 5% 6% 45%	2389
	21st to end	Night	12% 6% 3 7% 4 3 4 4 5% 5% 49%	1840
March	1st to 10th	Night	13% 7% 2 4 3 3 2 3 4 5% 53%	3419
	11th to 20th	Night	10% 5% 2 4 2 3 3 3 6% 7% 56%	3480
	21st to end	Night	15% 9% 3 7% 4 4 4 3 5% 6% 41%	3817
April	1st to 10th	Night	10% 5% 2 6% 3 3 5% 3 5% 6% 51%	2018
	11th to 20th	Night	14% 7% 3 6% 3 3 4 3 5% 5% 48%	1875
	21st to end	Night	17% 6% 2 6% 4 4 3 3 5% 6% 43%	1727
May	1st to 10th	Night	15% 8% 2 6% 4 4 5% 4 5% 6% 40%	2823
	11th to 20th	Night	15% 6% 2 6% 3 4 3 3 5% 7% 45%	2823
	21st to end	Night	11% 5% 2 4 4 3 3 3 5% 7% 54%	3090
June	1st to 10th	Night	5% 3 1 4 4 4 5% 5% 6% 10% 54%	1639
	11th to 20th	Night	4 3 2 5% 3 4 4 5% 8% 10% 52%	1527
	21st to end	Night	5% 3 2 4 2 4 4 3 6% 9% 59%	1710
July	1st to 10th	Night	9% 7% 2 6% 4 3 4 4 5% 6% 50%	2850
	11th to 20th	Night	2 2 2 4 3 3 4 3 6% 10% 60%	2850
	21st to end	Night	7% 3 2 5% 4 4 5% 4 9% 10% 45%	3098
August	1st to 10th	Night	2 2 1 3 4 4 4 5% 6% 10% 58%	2836
	11th to 20th	Night	8% 6% 2 6% 4 4 4 3 5% 8% 50%	2798
	21st to end	Night	3 3 2 6% 4 3 4 3 5% 7% 60%	3347
September	1st to 10th	Night	10% 4 2 4 3 4 4 3 3 5% 57%	1933
	11th to 20th	Night	9% 4 1 5% 3 3 4 3 5% 8% 54%	2090
	21st to end	Night	6% 4 2 4 4 3 4 3 4 6% 59%	2090
October	1st to 10th	Night	11% 3 2 3 3 3 3 3 4 7% 57%	2243
	11th to 20th	Night	12% 5% 1 4 3 2 3 2 3 5% 59%	2280
	21st to end	Night	14% 7% 3 5% 3 2 3 2 4 5% 53%	2508
November	1st to 10th	Night	10% 4 2 4 3 3 3 2 4 5% 61%	2286
	11th to 20th	Night	10% 7% 2 4 3 3 3 3 5% 7% 54%	2470
	21st to end	Night	15% 7% 2 4 3 2 2 2 4 5% 54%	2629
December	1st to 10th	Night	10% 8% 2 6% 4 4 4 3 5% 7% 48%	2660
	11th to 20th	Night	12% 7% 3 6% 4 3 4 4 5% 6% 46%	3279
	21st to end	Night	19% 15% 5% 8% 5% 4 3 2 4 4 32%	4560

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	46% 6% 10% 24% 13% 1	2848
	11th to 20th	Day	49% 4 15% 21% 12% 1	2850
	21st to end	Day	49% 5% 11% 19% 14% 1	3135
February	1st to 10th	Day	46% 5% 12% 25% 10% 3	1710
	11th to 20th	Day	43% 5% 11% 24% 14% 3	1701
	21st to end	Day	39% 5% 11% 23% 17% 5%	1613
March	1st to 10th	Day	37% 5% 9% 22% 23% 4	3436
	11th to 20th	Day	29% 6% 13% 28% 21% 3	3480
	21st to end	Day	46% 7% 13% 27% 6% 1	3814
April	1st to 10th	Day	39% 5% 11% 24% 19% 3	2161
	11th to 20th	Day	41% 6% 12% 23% 16% 1	2254
	21st to end	Day	47% 6% 11% 23% 11% 1	2450
May	1st to 10th	Day	46% 8% 9% 21% 15% 2	4120
	11th to 20th	Day	39% 8% 14% 24% 15%	4086
	21st to end	Day	38% 8% 13% 26% 14% 2	4489
June	1st to 10th	Day	27% 10% 17% 28% 16% 1	2527
	11th to 20th	Day	31% 8% 13% 29% 18% 2	2636
	21st to end	Day	26% 8% 15% 29% 18% 3	2470
July	1st to 10th	Day	38% 7% 12% 22% 18% 3	4056
	11th to 20th	Day	25% 7% 12% 35% 18% 3	4051
	21st to end	Day	29% 10% 17% 29% 14% 2	4325
August	1st to 10th	Day	28% 7% 12% 27% 22% 4	4090
	11th to 20th	Day	35% 6% 16% 26% 15% 2	4080
	21st to end	Day	25% 6% 14% 34% 16% 4	4312
September	1st to 10th	Day	31% 4 12% 26% 19% 7%	2242
	11th to 20th	Day	31% 6% 11% 27% 23% 2	2090
	21st to end	Day	30% 5% 10% 25% 26% 4	2090
October	1st to 10th	Day	19% 3 7% 22% 40% 9%	3176
	11th to 20th	Day	18% 2 5% 29% 35% 11%	3140
	21st to end	Day	30% 3 10% 26% 27% 4	3428
November	1st to 10th	Day	30% 5% 12% 29% 20% 5%	1861
	11th to 20th	Day	32% 4 9% 27% 23% 4	1710
	21st to end	Day	38% 3 8% 27% 22% 2	1546
December	1st to 10th	Day	36% 5% 13% 31% 14% 1	1520
	11th to 20th	Day	44% 5% 10% 25% 14% 2	1915
	21st to end	Day	57% 6% 11% 17% 8% 2	3102
January	1st to 10th	Night	45% 5% 14% 23% 12% 2	4108
	11th to 20th	Night	45% 6% 11% 22% 14% 1	4120
	21st to end	Night	47% 5% 14% 20% 13% 2	4532
February	1st to 10th	Night	44% 6% 11% 21% 15% 3	2470
	11th to 20th	Night	40% 5% 11% 24% 16% 3	2390
	21st to end	Night	37% 5% 8% 23% 20% 8%	1840
March	1st to 10th	Night	33% 6% 9% 26% 23% 4	3419
	11th to 20th	Night	26% 5% 11% 26% 28% 4	3480
	21st to end	Night	42% 8% 16% 23% 10% 1	3817
April	1st to 10th	Night	34% 5% 11% 23% 22% 5%	2018
	11th to 20th	Night	37% 6% 9% 25% 19% 3	1875
	21st to end	Night	41% 6% 12% 25% 14% 2	1727
May	1st to 10th	Night	40% 12% 14% 19% 14% 3	2850
	11th to 20th	Night	38% 8% 13% 27% 14% 1	2824
	21st to end	Night	29% 7% 13% 30% 20% 1	3099
June	1st to 10th	Night	23% 9% 18% 31% 16% 3	1639
	11th to 20th	Night	25% 8% 15% 31% 19% 2	1527
	21st to end	Night	21% 6% 13% 34% 22% 4	1710
July	1st to 10th	Night	34% 7% 11% 24% 19% 5%	2805
	11th to 20th	Night	19% 6% 14% 36% 22% 3	2796
	21st to end	Night	29% 8% 19% 30% 14% 1	2999
August	1st to 10th	Night	20% 7% 18% 28% 20% 7%	2826
	11th to 20th	Night	31% 6% 14% 26% 20% 2	2825
	21st to end	Night	24% 4 12% 38% 17% 4	3347
September	1st to 10th	Night	28% 7% 9% 26% 21% 9%	1933
	11th to 20th	Night	28% 6% 11% 26% 24% 4	2090
	21st to end	Night	26% 5% 8% 25% 30% 5%	2090
October	1st to 10th	Night	18% 4 6% 18% 47% 8%	3750
	11th to 20th	Night	21% 3 5% 26% 32% 14%	3779
	21st to end	Night	30% 4 8% 29% 26% 4	4120
November	1st to 10th	Night	27% 4 12% 27% 25% 6%	2286
	11th to 20th	Night	31% 4 9% 27% 25% 4	2470
	21st to end	Night	35% 3 9% 28% 21% 4	2629
December	1st to 10th	Night	36% 6% 13% 27% 17% 1	2660
	11th to 20th	Night	37% 5% 10% 29% 17% 2	3281
	21st to end	Night	55% 6% 8% 20% 9% 2	4560

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% 15% 33% 22% 8%	270
	11th to 20th	Day	25% 14% 40% 18% 3	270
	21st to end	Day	12% 11% 49% 23% 3 1	297
February	1st to 10th	Day	24% 18% 34% 20% 3 1	270
	11th to 20th	Day	17% 17% 45% 15% 6%	270
	21st to end	Day	14% 28% 40% 14% 3	225
March	1st to 10th	Day	18% 18% 39% 23% 3	270
	11th to 20th	Day	24% 14% 36% 20% 6%	270
	21st to end	Day	27% 23% 33% 14% 2 1	297
April	1st to 10th	Day	19% 20% 35% 19% 7%	341
	11th to 20th	Day	20% 16% 37% 21% 6%	452
	21st to end	Day	22% 13% 37% 20% 8% 1	630
May	1st to 10th	Day	20% 14% 36% 21% 8% 1	653
	11th to 20th	Day	19% 10% 30% 26% 14% 2	675
	21st to end	Day	17% 11% 28% 23% 16% 5%	734
June	1st to 10th	Day	6% 3 21% 36% 25% 8%	680
	11th to 20th	Day	8% 3 29% 36% 21% 4	680
	21st to end	Day	7% 5% 34% 36% 17% 2	680
July	1st to 10th	Day	11% 3 14% 32% 28% 12%	671
	11th to 20th	Day	4 1 19% 37% 30% 8%	668
	21st to end	Day	9% 2 15% 37% 29% 7%	739
August	1st to 10th	Day	9% 2 14% 38% 30% 6%	676
	11th to 20th	Day	8% 2 18% 37% 29% 5%	665
	21st to end	Day	9% 1 15% 30% 35% 10%	620
September	1st to 10th	Day	13% 2 12% 37% 30% 6%	452
	11th to 20th	Day	5% 3 18% 40% 29% 6%	300
	21st to end	Day	14% 5% 23% 38% 16% 4	300
October	1st to 10th	Day	12% 8% 29% 26% 18% 8%	300
	11th to 20th	Day	8% 16% 40% 26% 9% 1	300
	21st to end	Day	21% 13% 39% 20% 5% 2	330
November	1st to 10th	Day	18% 11% 33% 27% 8% 3	279
	11th to 20th	Day	19% 16% 31% 24% 9% 1	270
	21st to end	Day	23% 13% 35% 22% 8%	270
December	1st to 10th	Day	9% 16% 38% 27% 7% 3	270
	11th to 20th	Day	19% 14% 35% 24% 6% 1	270
	21st to end	Day	23% 20% 39% 17% 2	297
January	1st to 10th	Night	12% 12% 39% 30% 6%	950
	11th to 20th	Night	15% 14% 38% 27% 6% 1	950
	21st to end	Night	13% 14% 39% 30% 3	1045
February	1st to 10th	Night	17% 13% 41% 25% 3	950
	11th to 20th	Night	17% 13% 38% 28% 3	915
	21st to end	Night	18% 13% 40% 24% 5% 1	584
March	1st to 10th	Night	14% 13% 43% 27% 4	570
	11th to 20th	Night	18% 12% 38% 27% 6%	570
	21st to end	Night	24% 14% 34% 24% 4	627
April	1st to 10th	Night	13% 14% 41% 26% 6%	570
	11th to 20th	Night	17% 15% 35% 28% 6%	563
	21st to end	Night	19% 12% 35% 27% 7% 1	570
May	1st to 10th	Night	18% 7% 35% 32% 6% 1	570
	11th to 20th	Night	16% 6% 30% 35% 13%	561
	21st to end	Night	12% 5% 29% 34% 17% 2	617
June	1st to 10th	Night	5% 4 21% 44% 25% 1	570
	11th to 20th	Night	5% 4 27% 44% 19% 1	570
	21st to end	Night	5% 3 32% 45% 15%	570
July	1st to 10th	Night	9% 2 14% 43% 30% 2	555
	11th to 20th	Night	3 1 17% 49% 26% 3	552
	21st to end	Night	7% 2 13% 46% 30% 2	624
August	1st to 10th	Night	6% 1 15% 47% 30% 2	567
	11th to 20th	Night	7% 2 13% 45% 31% 2	564
	21st to end	Night	6% 1 13% 43% 35% 2	627
September	1st to 10th	Night	11% 1 18% 45% 23% 2	570
	11th to 20th	Night	10% 2 22% 40% 22% 4	570
	21st to end	Night	8% 4 23% 42% 21% 2	570
October	1st to 10th	Night	12% 4 28% 35% 19% 2	723
	11th to 20th	Night	16% 7% 39% 30% 8%	760
	21st to end	Night	17% 12% 33% 28% 9%	836
November	1st to 10th	Night	11% 10% 35% 33% 11% 1	778
	11th to 20th	Night	13% 13% 35% 31% 7%	950
	21st to end	Night	19% 11% 33% 31% 6%	950
December	1st to 10th	Night	16% 11% 36% 30% 6% 1	950
	11th to 20th	Night	19% 10% 37% 28% 5%	950
	21st to end	Night	20% 14% 36% 26% 4	1045

Page generated at 2024-11-01 21:47:51. Version ac07

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