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 2024-04-03.

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	12% 7% 3 5% 5% 3 4 4 5% 7% 45%	78870
	Night	11% 7% 3 5% 4 3 4 4 5% 6% 48%	81279
Transparency	Day	38% 6% 12% 25% 16% 3	78593
	Night	36% 6% 12% 25% 18% 3	81076
Seeing	Day	14% 9% 28% 28% 17% 4	14716
	Night	14% 9% 32% 33% 12% 1	24782

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% 9% 3 8% 5% 3 4 4 5% 6% 38%	2847
	11th to 20th	Day	10% 10% 4 7% 7% 5% 6% 3 3 5% 39%	2850
	21st to end	Day	13% 14% 6% 7% 5% 2 3 3 4 5% 37%	3135
February	1st to 10th	Day	14% 10% 4 6% 5% 3 4 3 3 6% 42%	1710
	11th to 20th	Day	13% 7% 4 7% 5% 3 5% 3 4 6% 43%	1692
	21st to end	Day	12% 7% 3 6% 4 3 4 5% 4 7% 45%	1613
March	1st to 10th	Day	11% 8% 3 7% 5% 3 5% 5% 5% 6% 43%	2090
	11th to 20th	Day	18% 9% 3 4 5% 2 3 4 4 6% 41%	2090
	21st to end	Day	18% 11% 4 7% 5% 3 4 4 5% 6% 34%	2299
April	1st to 10th	Day	14% 7% 2 6% 5% 2 4 4 4 6% 46%	2069
	11th to 20th	Day	15% 7% 3 6% 5% 3 4 4 5% 6% 41%	2134
	21st to end	Day	19% 7% 3 6% 6% 3 4 4 4 6% 37%	2321
May	1st to 10th	Day	18% 9% 3 6% 5% 3 4 4 4 7% 36%	2340
	11th to 20th	Day	16% 6% 3 5% 5% 3 4 4 5% 8% 41%	2302
	21st to end	Day	15% 7% 3 7% 6% 4 5% 5% 6% 8% 35%	2531
June	1st to 10th	Day	6% 3 2 3 4 4 4 6% 8% 11% 48%	2394
	11th to 20th	Day	7% 4 3 5% 5% 3 5% 4 7% 9% 49%	2498
	21st to end	Day	7% 3 1 3 5% 3 5% 4 6% 9% 54%	2340
July	1st to 10th	Day	10% 5% 2 4 5% 3 5% 5% 7% 9% 45%	2340
	11th to 20th	Day	4 2 1 4 4 4 5% 5% 6% 9% 55%	2340
	21st to end	Day	8% 4 2 5% 5% 3 5% 6% 7% 8% 46%	2546
August	1st to 10th	Day	7% 4 2 5% 4 4 5% 6% 6% 10% 46%	2328
	11th to 20th	Day	8% 4 2 4 4 3 4 5% 6% 8% 52%	2301
	21st to end	Day	8% 3 1 5% 4 3 4 5% 6% 8% 53%	2453
September	1st to 10th	Day	14% 5% 2 4 3 2 3 4 4 7% 52%	2124
	11th to 20th	Day	9% 5% 2 4 5% 3 4 5% 5% 7% 50%	1980
	21st to end	Day	8% 4 2 4 5% 2 4 4 5% 6% 54%	1980
October	1st to 10th	Day	11% 6% 2 5% 3 3 3 4 4 7% 51%	1816
	11th to 20th	Day	12% 6% 2 4 3 2 3 3 4 5% 58%	1800
	21st to end	Day	15% 6% 2 5% 4 2 3 3 3 5% 50%	1980
November	1st to 10th	Day	9% 6% 2 4 3 2 4 4 4 6% 57%	1831
	11th to 20th	Day	13% 5% 3 4 3 2 3 3 3 7% 54%	1710
	21st to end	Day	15% 8% 3 4 4 2 2 2 3 5% 51%	1546
December	1st to 10th	Day	10% 8% 3 4 4 3 4 3 4 8% 49%	1520
	11th to 20th	Day	12% 9% 4 6% 5% 3 5% 4 4 5% 43%	1918
	21st to end	Day	16% 14% 7% 8% 6% 3 5% 4 5% 5% 27%	3102
January	1st to 10th	Night	9% 9% 3 12% 6% 3 4 4 3 5% 42%	4108
	11th to 20th	Night	10% 8% 3 7% 7% 5% 7% 5% 5% 5% 39%	4120
	21st to end	Night	16% 11% 4 7% 5% 3 3 4 4 5% 38%	4532
February	1st to 10th	Night	11% 11% 4 6% 6% 3 4 4 5% 6% 41%	2470
	11th to 20th	Night	12% 9% 4 5% 4 2 4 4 5% 6% 45%	2389
	21st to end	Night	13% 5% 3 6% 4 2 4 5% 5% 5% 49%	1840
March	1st to 10th	Night	12% 6% 2 5% 4 2 3 4 5% 6% 50%	2090
	11th to 20th	Night	15% 7% 2 5% 4 3 4 4 5% 7% 45%	2090
	21st to end	Night	19% 9% 3 6% 5% 3 4 5% 4 6% 37%	2299
April	1st to 10th	Night	10% 5% 2 6% 4 2 4 5% 4 7% 51%	1934
	11th to 20th	Night	14% 7% 3 5% 4 2 4 4 4 6% 47%	1775
	21st to end	Night	17% 6% 2 5% 5% 3 3 4 5% 6% 44%	1637
May	1st to 10th	Night	16% 7% 2 6% 5% 3 5% 5% 5% 7% 41%	1620
	11th to 20th	Night	14% 4 2 5% 3 3 4 3 4 7% 50%	1593
	21st to end	Night	11% 5% 3 4 5% 3 4 5% 6% 9% 46%	1745
June	1st to 10th	Night	4 2 1 3 4 3 4 6% 6% 10% 55%	1553
	11th to 20th	Night	4 3 2 4 4 3 5% 5% 7% 10% 53%	1446
	21st to end	Night	5% 3 2 3 3 3 4 4 6% 9% 60%	1620
July	1st to 10th	Night	7% 4 2 4 3 3 4 5% 6% 9% 53%	1620
	11th to 20th	Night	2 2 1 3 3 3 4 4 5% 11% 61%	1620
	21st to end	Night	7% 3 2 5% 5% 2 5% 4 7% 9% 51%	1772
August	1st to 10th	Night	4 3 2 3 5% 3 4 6% 6% 12% 51%	1611
	11th to 20th	Night	5% 4 2 5% 4 3 4 4 5% 8% 57%	1600
	21st to end	Night	5% 3 2 4 5% 2 3 4 4 7% 61%	1903
September	1st to 10th	Night	11% 4 2 3 4 3 4 5% 3 6% 56%	1831
	11th to 20th	Night	9% 4 1 4 3 2 4 4 5% 8% 54%	1980
	21st to end	Night	6% 4 2 4 4 2 4 4 4 6% 60%	1980
October	1st to 10th	Night	11% 3 2 3 4 2 3 4 5% 7% 55%	2124
	11th to 20th	Night	13% 5% 2 4 3 2 2 3 3 5% 58%	2160
	21st to end	Night	14% 6% 3 4 4 2 3 2 3 5% 53%	2376
November	1st to 10th	Night	9% 3 2 4 3 3 3 3 4 5% 61%	2243
	11th to 20th	Night	10% 6% 3 4 3 2 4 3 5% 7% 55%	2470
	21st to end	Night	16% 6% 2 4 3 2 3 3 3 5% 54%	2629
December	1st to 10th	Night	11% 7% 2 5% 4 2 4 4 5% 7% 48%	2660
	11th to 20th	Night	12% 7% 3 5% 5% 2 4 4 5% 6% 47%	3279
	21st to end	Night	19% 14% 5% 7% 5% 3 4 3 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	41% 6% 10% 22% 17% 4	2090
	11th to 20th	Day	44% 5% 10% 23% 15% 2	2090
	21st to end	Day	51% 6% 12% 21% 8% 2	2299
April	1st to 10th	Day	39% 5% 12% 23% 18% 2	2069
	11th to 20th	Day	42% 6% 12% 23% 15% 1	2134
	21st to end	Day	47% 6% 11% 23% 12% 1	2321
May	1st to 10th	Day	48% 7% 11% 20% 14% 1	2340
	11th to 20th	Day	42% 7% 15% 24% 12%	2306
	21st to end	Day	47% 9% 14% 20% 9% 1	2531
June	1st to 10th	Day	26% 10% 17% 29% 16% 1	2394
	11th to 20th	Day	31% 8% 13% 28% 18% 2	2498
	21st to end	Day	26% 8% 14% 30% 18% 3	2340
July	1st to 10th	Day	32% 9% 15% 26% 15% 3	2276
	11th to 20th	Day	23% 8% 16% 30% 18% 4	2271
	21st to end	Day	30% 8% 16% 29% 16% 1	2405
August	1st to 10th	Day	32% 9% 16% 27% 14% 2	2314
	11th to 20th	Day	29% 7% 12% 32% 17% 3	2301
	21st to end	Day	28% 8% 11% 25% 21% 7%	2453
September	1st to 10th	Day	32% 5% 13% 27% 17% 7%	2124
	11th to 20th	Day	31% 6% 11% 26% 23% 2	1980
	21st to end	Day	30% 6% 10% 25% 26% 3	1980
October	1st to 10th	Day	32% 5% 11% 28% 20% 3	1816
	11th to 20th	Day	31% 4 8% 26% 25% 6%	1800
	21st to end	Day	37% 4 11% 22% 19% 6%	1980
November	1st to 10th	Day	29% 5% 12% 29% 20% 5%	1831
	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	35% 5% 10% 24% 20% 5%	2090
	11th to 20th	Night	39% 6% 11% 22% 18% 4	2090
	21st to end	Night	48% 6% 12% 21% 12% 2	2299
April	1st to 10th	Night	34% 5% 11% 23% 22% 4	1934
	11th to 20th	Night	38% 5% 9% 26% 19% 3	1775
	21st to end	Night	41% 6% 12% 25% 15% 2	1637
May	1st to 10th	Night	41% 8% 12% 22% 15% 2	1620
	11th to 20th	Night	34% 7% 14% 27% 17% 1	1594
	21st to end	Night	34% 8% 18% 27% 11% 2	1746
June	1st to 10th	Night	23% 9% 19% 32% 15% 3	1553
	11th to 20th	Night	25% 8% 15% 31% 19% 3	1446
	21st to end	Night	21% 6% 13% 35% 22% 4	1620
July	1st to 10th	Night	27% 8% 15% 30% 16% 4	1575
	11th to 20th	Night	17% 6% 16% 34% 21% 5%	1566
	21st to end	Night	27% 7% 13% 31% 20% 1	1673
August	1st to 10th	Night	23% 9% 18% 32% 14% 3	1601
	11th to 20th	Night	26% 7% 12% 31% 23% 2	1600
	21st to end	Night	24% 5% 12% 27% 25% 7%	1903
September	1st to 10th	Night	29% 7% 10% 27% 19% 8%	1831
	11th to 20th	Night	28% 6% 11% 25% 24% 5%	1980
	21st to end	Night	25% 6% 9% 26% 30% 5%	1980
October	1st to 10th	Night	29% 6% 9% 24% 25% 6%	2124
	11th to 20th	Night	30% 4 7% 28% 24% 8%	2160
	21st to end	Night	35% 4 9% 22% 26% 5%	2376
November	1st to 10th	Night	26% 4 12% 28% 25% 6%	2243
	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	18% 20% 35% 19% 8%	313
	11th to 20th	Day	21% 16% 36% 21% 6%	412
	21st to end	Day	21% 14% 37% 19% 8% 1	581
May	1st to 10th	Day	20% 13% 35% 21% 9% 1	603
	11th to 20th	Day	20% 10% 30% 25% 13% 2	625
	21st to end	Day	18% 10% 28% 22% 17% 5%	679
June	1st to 10th	Day	6% 3 21% 35% 27% 8%	630
	11th to 20th	Day	8% 3 28% 36% 21% 4	630
	21st to end	Day	7% 5% 33% 36% 17% 2	630
July	1st to 10th	Day	11% 2 12% 33% 29% 13%	621
	11th to 20th	Day	4 1 17% 37% 32% 9%	618
	21st to end	Day	10% 1 14% 38% 29% 7%	684
August	1st to 10th	Day	9% 1 14% 38% 31% 6%	626
	11th to 20th	Day	7% 2 18% 37% 31% 6%	615
	21st to end	Day	9% 1 15% 30% 34% 11%	572
September	1st to 10th	Day	14% 2 12% 37% 29% 6%	414
	11th to 20th	Day	5% 2 18% 39% 30% 6%	270
	21st to end	Day	13% 5% 24% 38% 17% 4	270
October	1st to 10th	Day	13% 9% 30% 24% 17% 8%	270
	11th to 20th	Day	9% 17% 42% 23% 8%	270
	21st to end	Day	23% 13% 38% 20% 5% 2	297
November	1st to 10th	Day	17% 11% 33% 28% 9% 3	270
	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	14% 13% 41% 27% 6%	546
	11th to 20th	Night	18% 14% 35% 28% 6%	533
	21st to end	Night	19% 11% 35% 27% 7% 1	540
May	1st to 10th	Night	19% 7% 34% 33% 7% 1	540
	11th to 20th	Night	16% 6% 31% 35% 13%	531
	21st to end	Night	12% 5% 29% 34% 18% 2	584
June	1st to 10th	Night	5% 3 21% 44% 26% 1	540
	11th to 20th	Night	6% 4 26% 44% 19% 1	540
	21st to end	Night	5% 3 31% 46% 15%	540
July	1st to 10th	Night	9% 2 12% 43% 32% 2	525
	11th to 20th	Night	2 1 16% 50% 27% 3	522
	21st to end	Night	8% 2 12% 46% 31% 2	591
August	1st to 10th	Night	6% 1 14% 46% 30% 2	537
	11th to 20th	Night	7% 2 12% 45% 32% 2	534
	21st to end	Night	6% 2 13% 41% 36% 2	594
September	1st to 10th	Night	11% 1 19% 44% 22% 2	540
	11th to 20th	Night	10% 2 21% 40% 23% 4	540
	21st to end	Night	7% 5% 23% 42% 21% 2	540
October	1st to 10th	Night	13% 4 29% 33% 19% 2	684
	11th to 20th	Night	17% 7% 39% 28% 8%	720
	21st to end	Night	18% 11% 34% 28% 9%	792
November	1st to 10th	Night	10% 10% 35% 33% 11% 1	763
	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 2024-03-31 05:08:52. Version ac07

Copyright © 2024 Attilla Danko.