Katepwa Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Katepwa Lake clear sky chart from 2005-11-05 to 2017-09-19.

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 TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(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

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
39%
15935
12%
46581
8%
15897
43%
15897
21%
32665

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
30%
895
9%
2609
6%
895
32%
895
14%
1994
January16th to endNight
23%
960
10%
2688
4%
960
29%
960
12%
2106
February1st to 15thNight
34%
834
9%
2423
5%
834
38%
834
15%
1860
February16th to endNight
39%
632
15%
1952
12%
632
43%
632
17%
1455
March1st to 15thNight
38%
720
13%
2160
9%
720
41%
720
18%
1555
March16th to endNight
35%
633
14%
2012
10%
633
41%
633
16%
1468
April1st to 15thNight
39%
539
17%
1798
14%
539
46%
539
26%
1109
April16th to endNight
38%
540
13%
1565
9%
540
42%
540
21%
1120
May1st to 15thNight
40%
540
12%
1440
5%
540
43%
540
28%
956
May16th to endNight
42%
563
8%
1393
4%
561
44%
561
26%
983
June1st to 15thNight
43%
460
2%
1180
2%
460
43%
460
26%
822
June16th to endNight
46%
360
2%
1080
3%
360
47%
360
27%
694
July1st to 15thNight
59%
376
4%
1098
4%
376
61%
376
38%
619
July16th to endNight
64%
564
12%
1416
6%
531
66%
531
49%
768
August1st to 15thNight
65%
539
15%
1432
8%
536
69%
536
43%
821
August16th to endNight
61%
573
24%
1741
20%
573
67%
573
42%
926
September1st to 15thNight
53%
540
17%
1800
17%
540
58%
540
27%
1068
September16th to endNight
48%
504
22%
1827
19%
504
57%
504
28%
1047
October1st to 15thNight
42%
648
17%
1968
11%
648
47%
648
24%
1299
October16th to endNight
37%
880
15%
2288
7%
880
41%
880
24%
1630
November1st to 15thNight
32%
875
15%
2380
6%
875
38%
875
20%
1720
November16th to endNight
26%
900
13%
2673
6%
900
32%
900
15%
2026
December1st to 15thNight
25%
900
5%
2700
3%
900
27%
900
9%
2260
December16th to endNight
27%
960
9%
2958
5%
960
32%
960
10%
2359

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 ForecastData
Points
Cloud CoverDay
12%8%36%6%35%5%5%7%33%
48237
Night
10%9%47%6%35%5%5%7%33%
46733
Cloud CoverDay
12%8%36%6%35%5%5%7%33%
48246
Night
10%9%47%6%35%5%5%7%33%
46736
Cloud CoverDay
12%8%36%6%35%5%5%7%33%
48247
Night
10%9%48%6%35%5%5%7%33%
46738
TransparencyDay
49%5%15%21%7%
47905
Night
49%5%14%21%8%
46581
SeeingDay
15%7%26%28%17%4
6262
Night
14%6%27%33%15%1
15945

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
9%12%5%9%9%5%6%5%6%8%19%
1323
16th to endDay
7%11%7%12%10%47%45%8%22%
1536
February1st to 15thDay
8%12%6%12%8%5%9%7%5%5%19%
1450
16th to endDay
9%11%6%10%10%5%8%7%7%5%16%
1521
March1st to 15thDay
9%12%8%10%9%45%45%9%19%
1790
16th to endDay
13%11%47%6%35%5%6%9%25%
2211
April1st to 15thDay
10%9%36%6%35%5%5%9%32%
2150
16th to endDay
15%11%36%5%35%35%6%32%
2393
May1st to 15thDay
12%9%35%5%35%5%5%7%36%
2511
16th to endDay
19%7%26%6%35%45%6%31%
2718
June1st to 15thDay
18%6%36%6%46%5%6%7%29%
2778
16th to endDay
16%5%25%6%35%6%6%8%33%
2880
July1st to 15thDay
8%4145%35%5%5%8%46%
2791
16th to endDay
8%3143345%6%9%47%
2656
August1st to 15thDay
9%5%245%345%6%10%44%
2520
16th to endDay
11%413423446%52%
2457
September1st to 15thDay
12%6%24424346%47%
2160
16th to endDay
14%5%24413347%48%
1877
October1st to 15thDay
18%11%46%423346%32%
1648
16th to endDay
13%13%46%5%2445%6%33%
1584
November1st to 15thDay
13%12%5%9%7%45%34428%
1476
16th to endDay
11%13%5%8%7%4446%7%25%
1287
December1st to 15thDay
10%16%7%11%12%5%6%6%5%412%
1260
16th to endDay
8%16%5%11%10%46%5%47%17%
1260
January1st to 15thNight
8%13%5%10%8%37%6%7%8%21%
2609
16th to endNight
7%12%7%12%8%36%6%7%8%20%
2688
February1st to 15thNight
8%10%5%10%9%5%8%7%6%6%23%
2419
16th to endNight
6%11%6%11%8%47%5%5%6%25%
1952
March1st to 15thNight
7%11%5%8%8%5%5%447%31%
2147
16th to endNight
10%12%48%7%46%5%5%7%27%
2012
April1st to 15thNight
9%7%35%5%3446%7%42%
1798
16th to endNight
17%8%35%6%35%45%6%32%
1565
May1st to 15thNight
14%6%25%435%45%7%39%
1440
16th to endNight
17%5%25%4346%6%7%36%
1392
June1st to 15thNight
16%6%34336%5%5%6%38%
1180
16th to endNight
13%5%35%424448%43%
1080
July1st to 15thNight
7%322325%46%7%54%
1164
16th to endNight
5%21221345%10%59%
1512
August1st to 15thNight
8%3133245%47%56%
1440
16th to endNight
7%31422445%9%54%
1741
September1st to 15thNight
12%5%245%2345%7%47%
1800
16th to endNight
12%5%234235%5%6%48%
1827
October1st to 15thNight
15%9%4342345%7%38%
1968
16th to endNight
11%12%46%5%25%447%35%
2288
November1st to 15thNight
15%10%46%5%34445%34%
2380
16th to endNight
10%13%6%9%7%35%45%5%27%
2673
December1st to 15thNight
9%15%7%14%9%5%6%6%5%5%15%
2700
16th to endNight
7%10%7%14%10%5%6%6%6%7%17%
2958

Percentage Cloud Cover NW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
10%11%5%10%9%5%7%47%8%20%
1323
16th to endDay
6%11%7%12%10%47%5%5%7%22%
1536
February1st to 15thDay
9%12%5%12%8%48%8%5%5%19%
1450
16th to endDay
9%12%6%10%9%5%8%7%7%5%17%
1521
March1st to 15thDay
9%13%7%10%8%5%5%45%8%20%
1800
16th to endDay
13%11%48%5%35%5%6%8%26%
2210
April1st to 15thDay
11%9%36%6%35%5%5%9%32%
2150
16th to endDay
15%11%36%5%3435%6%33%
2393
May1st to 15thDay
13%8%36%5%345%5%8%37%
2511
16th to endDay
19%7%26%5%3446%7%31%
2718
June1st to 15thDay
18%6%26%6%35%5%5%7%30%
2778
16th to endDay
16%5%25%5%36%6%6%8%33%
2880
July1st to 15thDay
9%415%435%5%5%8%46%
2791
16th to endDay
8%3144345%6%9%48%
2656
August1st to 15thDay
9%4235%345%6%10%44%
2520
16th to endDay
11%413423447%52%
2457
September1st to 15thDay
13%6%23424446%47%
2160
16th to endDay
13%5%23413347%48%
1877
October1st to 15thDay
19%11%5%5%423346%33%
1648
16th to endDay
14%12%5%6%5%33446%33%
1584
November1st to 15thDay
13%11%5%8%7%45%34429%
1476
16th to endDay
11%13%6%7%7%445%5%7%26%
1287
December1st to 15thDay
10%16%7%11%12%5%6%6%6%412%
1260
16th to endDay
9%16%5%11%10%5%6%5%5%6%17%
1260
January1st to 15thNight
8%12%5%10%7%36%7%7%8%22%
2609
16th to endNight
7%12%6%12%7%36%6%6%8%20%
2688
February1st to 15thNight
7%10%5%10%8%5%8%6%5%6%23%
2412
16th to endNight
6%11%7%11%8%46%6%5%7%25%
1952
March1st to 15thNight
7%10%5%9%8%45%448%30%
2160
16th to endNight
11%12%48%7%46%45%7%28%
2009
April1st to 15thNight
10%7%35%5%3446%7%41%
1798
16th to endNight
18%7%25%6%35%45%6%33%
1565
May1st to 15thNight
14%6%25%425%45%7%39%
1439
16th to endNight
17%425%5%346%5%8%36%
1393
June1st to 15thNight
17%5%24426%5%5%6%38%
1180
16th to endNight
13%5%25%4245%48%43%
1080
July1st to 15thNight
7%312325%5%5%7%54%
1164
16th to endNight
5%21222345%10%59%
1512
August1st to 15thNight
8%313224447%56%
1440
16th to endNight
8%313323449%55%
1741
September1st to 15thNight
12%42443345%7%47%
1800
16th to endNight
12%5%2332345%6%49%
1827
October1st to 15thNight
14%10%3432345%7%39%
1968
16th to endNight
11%11%5%6%5%25%45%6%36%
2288
November1st to 15thNight
15%10%46%5%34445%34%
2380
16th to endNight
10%13%6%8%7%36%5%46%27%
2673
December1st to 15thNight
9%14%6%13%9%46%6%5%6%15%
2700
16th to endNight
8%10%6%14%10%5%6%6%6%7%17%
2958

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
10%12%5%10%8%6%7%5%5%8%19%
1323
16th to endDay
6%12%7%12%9%47%447%21%
1536
February1st to 15thDay
8%12%6%11%8%5%9%6%6%5%19%
1450
16th to endDay
9%11%6%10%9%5%10%6%7%5%16%
1521
March1st to 15thDay
9%13%8%10%9%46%45%7%19%
1800
16th to endDay
13%11%47%6%35%5%6%9%25%
2211
April1st to 15thDay
10%9%37%6%35%5%6%8%33%
2150
16th to endDay
15%10%36%5%3445%6%33%
2393
May1st to 15thDay
12%9%35%5%35%45%7%37%
2511
16th to endDay
19%7%25%6%35%45%7%31%
2718
June1st to 15thDay
18%6%26%6%45%5%6%7%30%
2778
16th to endDay
16%6%25%5%35%6%6%8%34%
2880
July1st to 15thDay
9%4245%35%5%5%8%46%
2791
16th to endDay
8%3144245%6%8%48%
2656
August1st to 15thDay
9%425%4345%6%10%44%
2520
16th to endDay
12%413423446%51%
2457
September1st to 15thDay
13%5%15%424436%47%
2160
16th to endDay
14%5%23423347%48%
1877
October1st to 15thDay
18%12%46%423347%32%
1648
16th to endDay
13%12%5%6%5%245%5%6%32%
1584
November1st to 15thDay
13%12%5%9%7%4444428%
1476
16th to endDay
11%13%6%8%7%46%36%6%25%
1287
December1st to 15thDay
11%14%7%12%12%5%7%6%5%412%
1260
16th to endDay
8%18%5%12%10%5%5%5%46%17%
1260
January1st to 15thNight
9%12%5%10%7%47%5%7%8%21%
2609
16th to endNight
7%12%6%12%8%36%6%7%7%20%
2688
February1st to 15thNight
8%10%5%9%9%5%8%7%5%6%23%
2412
16th to endNight
5%12%6%11%8%46%5%5%6%25%
1952
March1st to 15thNight
6%12%5%8%9%45%45%7%30%
2160
16th to endNight
10%11%48%7%46%5%5%7%27%
2012
April1st to 15thNight
9%8%35%5%3445%8%42%
1798
16th to endNight
17%9%36%6%35%46%6%32%
1565
May1st to 15thNight
14%6%25%5%35%5%5%7%39%
1439
16th to endNight
17%5%25%3445%6%8%36%
1392
June1st to 15thNight
16%6%24435%5%5%6%38%
1180
16th to endNight
13%6%25%425%447%43%
1080
July1st to 15thNight
7%313325%45%7%53%
1164
16th to endNight
5%21321345%9%59%
1512
August1st to 15thNight
8%2133145%48%55%
1440
16th to endNight
8%314323448%55%
1741
September1st to 15thNight
11%6%24424447%47%
1800
16th to endNight
11%5%244235%46%48%
1827
October1st to 15thNight
15%10%3432435%7%38%
1968
16th to endNight
12%11%46%42435%6%35%
2288
November1st to 15thNight
14%11%46%5%34445%34%
2380
16th to endNight
10%13%5%9%7%35%5%45%26%
2673
December1st to 15thNight
9%14%7%13%9%5%6%6%45%15%
2700
16th to endNight
7%11%6%15%10%5%6%5%5%7%17%
2958

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
61%5%12%16%3
1323
16th to endDay
61%5%12%14%5%
1536
February1st to 15thDay
65%414%12%3
1450
16th to endDay
64%5%10%12%6%
1521
March1st to 15thDay
63%6%13%13%3
1800
16th to endDay
54%6%15%17%4
2211
April1st to 15thDay
47%6%16%21%6%
2150
16th to endDay
50%415%17%9%1
2393
May1st to 15thDay
45%5%11%26%10%
2511
16th to endDay
51%413%17%12%
2722
June1st to 15thDay
51%5%13%21%7%
2778
16th to endDay
46%7%19%19%6%
2880
July1st to 15thDay
35%6%20%30%7%
2628
16th to endDay
31%6%20%31%8%
2489
August1st to 15thDay
34%6%25%25%7%
2504
16th to endDay
32%5%15%35%10%
2457
September1st to 15thDay
37%414%29%12%1
2160
16th to endDay
36%314%32%11%1
1877
October1st to 15thDay
52%412%23%6%
1648
16th to endDay
50%418%22%3
1584
November1st to 15thDay
58%413%15%7%
1476
16th to endDay
58%5%16%13%5%
1287
December1st to 15thDay
72%5%9%10%1
1260
16th to endDay
66%411%15%1
1260
January1st to 15thNight
58%5%14%16%4
2609
16th to endNight
59%7%14%12%5%
2688
February1st to 15thNight
59%5%13%15%5%
2423
16th to endNight
57%311%19%7%
1952
March1st to 15thNight
53%415%21%4
2160
16th to endNight
54%5%13%20%4
2012
April1st to 15thNight
40%414%26%12%1
1798
16th to endNight
51%412%16%11%2
1565
May1st to 15thNight
43%412%24%14%1
1440
16th to endNight
44%6%14%17%14%1
1393
June1st to 15thNight
44%5%14%23%10%1
1180
16th to endNight
40%5%17%28%7%
1080
July1st to 15thNight
28%6%19%36%9%
1098
16th to endNight
20%6%21%36%13%1
1416
August1st to 15thNight
26%5%24%33%8%
1432
16th to endNight
26%315%36%16%1
1741
September1st to 15thNight
36%5%12%27%16%1
1800
16th to endNight
35%413%29%15%
1827
October1st to 15thNight
44%416%25%8%
1968
16th to endNight
48%317%23%5%
2288
November1st to 15thNight
51%415%17%9%1
2380
16th to endNight
57%5%14%17%3
2673
December1st to 15thNight
69%6%11%11%1
2700
16th to endNight
64%5%11%13%5%
2958

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
12%7%16%34%24%4
81
16th to endDay
16%11%29%23%17%1
96
February1st to 15thDay
16%7%28%32%14%
90
16th to endDay
25%125%27%17%2
81
March1st to 15thDay
15%6%48%20%8%
90
16th to endDay
25%9%28%26%9%1
252
April1st to 15thDay
11%15%39%26%6%
269
16th to endDay
19%6%25%29%17%1
434
May1st to 15thDay
18%8%29%29%11%1
468
16th to endDay
18%5%25%26%16%6%
517
June1st to 15thDay
16%11%26%26%16%3
495
16th to endDay
15%10%23%30%15%4
495
July1st to 15thDay
11%421%32%25%6%
475
16th to endDay
7%5%30%31%20%4
515
August1st to 15thDay
10%5%17%34%24%8%
493
16th to endDay
12%321%31%23%7%
430
September1st to 15thDay
15%7%35%21%15%3
315
16th to endDay
15%8%27%28%13%6%
128
October1st to 15thDay
35%6%26%16%12%2
90
16th to endDay
28%7%25%19%15%4
96
November1st to 15thDay
20%5%26%30%13%4
90
16th to endDay
22%8%24%26%15%2
90
December1st to 15thDay
27%27%25%14%4
90
16th to endDay
18%440%25%9%1
82
January1st to 15thNight
14%9%29%32%12%1
900
16th to endNight
14%13%34%29%8%
960
February1st to 15thNight
13%6%30%30%15%3
839
16th to endNight
9%424%38%17%4
632
March1st to 15thNight
12%6%28%34%14%2
720
16th to endNight
16%5%28%31%16%1
633
April1st to 15thNight
13%7%31%33%12%
539
16th to endNight
21%427%33%12%
540
May1st to 15thNight
16%6%27%33%14%1
540
16th to endNight
21%5%24%30%16%1
563
June1st to 15thNight
19%426%34%13%1
460
16th to endNight
15%5%26%33%19%
360
July1st to 15thNight
9%223%40%23%1
376
16th to endNight
6%321%43%23%2
564
August1st to 15thNight
9%118%40%25%3
539
16th to endNight
9%220%41%24%1
573
September1st to 15thNight
13%421%36%21%2
540
16th to endNight
13%427%38%14%1
504
October1st to 15thNight
20%6%23%31%16%1
648
16th to endNight
18%7%26%36%10%
880
November1st to 15thNight
18%9%30%28%11%1
875
16th to endNight
16%9%35%30%7%1
900
December1st to 15thNight
16%6%30%30%13%2
900
16th to endNight
11%6%31%31%15%3
960
Page generated at 2017-09-20 02:49:44. Version ac04

Copyright 2017 A. Danko


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