Chamberlain Creek Rest Stop
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chamberlain Creek Rest Stop clear sky chart from 2005-11-05 to 2017-09-17.

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
60%
15242
23%
46923
21%
15205
63%
15205
31%
27962

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
50%
717
14%
2370
14%
716
52%
716
18%
1631
January16th to endNight
51%
768
24%
2496
24%
768
54%
768
22%
1655
February1st to 15thNight
46%
698
19%
2288
19%
698
49%
698
18%
1577
February16th to endNight
43%
632
16%
1948
14%
632
48%
632
20%
1353
March1st to 15thNight
45%
720
11%
1980
10%
720
48%
720
19%
1462
March16th to endNight
44%
768
16%
2112
12%
768
48%
768
23%
1467
April1st to 15thNight
40%
719
17%
1814
8%
719
45%
719
22%
1291
April16th to endNight
55%
681
21%
1761
11%
681
59%
681
37%
1050
May1st to 15thNight
61%
539
25%
1619
18%
539
66%
539
40%
865
May16th to endNight
59%
419
22%
1542
20%
419
65%
419
28%
847
June1st to 15thNight
61%
360
21%
1440
23%
360
70%
360
30%
747
June16th to endNight
78%
360
32%
1440
42%
360
83%
360
53%
554
July1st to 15thNight
88%
398
30%
1418
36%
398
89%
398
69%
506
July16th to endNight
87%
564
35%
1593
34%
531
88%
531
67%
661
August1st to 15thNight
89%
538
35%
1611
30%
535
90%
535
67%
675
August16th to endNight
87%
705
40%
1851
28%
705
88%
705
68%
863
September1st to 15thNight
84%
720
39%
1800
27%
720
86%
720
71%
859
September16th to endNight
74%
664
34%
1850
29%
664
78%
664
52%
952
October1st to 15thNight
66%
660
27%
1980
29%
660
71%
660
41%
1062
October16th to endNight
63%
704
26%
2112
27%
704
66%
704
31%
1283
November1st to 15thNight
56%
700
20%
2170
18%
700
60%
700
24%
1415
November16th to endNight
55%
720
17%
2520
18%
720
58%
720
23%
1601
December1st to 15thNight
48%
720
17%
2520
17%
720
51%
720
18%
1701
December16th to endNight
40%
768
16%
2688
16%
768
44%
768
16%
1885

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%5%23323346%53%
47848
Night
13%5%24323346%50%
47112
TransparencyDay
31%49%20%21%12%
47537
Night
35%410%18%19%11%
46924
SeeingDay
17%11%25%28%12%4
6030
Night
16%312%27%30%9%
15253

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
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
19%7%35%5%33346%37%
1566
16th to endDay
23%7%25%323235%40%
1728
February1st to 15thDay
25%6%24323346%36%
1576
16th to endDay
23%8%24433447%33%
1523
March1st to 15thDay
25%9%35%423346%30%
1980
16th to endDay
22%6%34435%447%33%
2112
April1st to 15thDay
18%8%35%435%45%7%33%
2133
16th to endDay
13%6%23323347%49%
2197
May1st to 15thDay
8%5%12223347%58%
2331
16th to endDay
9%7%24423346%51%
2569
June1st to 15thDay
8%5%24313436%55%
2520
16th to endDay
5%22112236%70%
2520
July1st to 15thDay
112211235%77%
2454
16th to endDay
221211125%77%
2468
August1st to 15thDay
112212235%76%
2340
16th to endDay
21212335%75%
2351
September1st to 15thDay
121212345%73%
2160
16th to endDay
4211212236%70%
1810
October1st to 15thDay
10%413213345%58%
1650
16th to endDay
12%5%24322338%51%
1760
November1st to 15thDay
13%4245%3445%8%42%
1684
16th to endDay
18%5%35%424436%41%
1440
December1st to 15thDay
23%8%24224447%35%
1440
16th to endDay
28%7%2442335%5%32%
1536
January1st to 15thNight
18%6%26%5%335%47%35%
2370
16th to endNight
22%6%24423246%40%
2496
February1st to 15thNight
21%6%26%5%34435%36%
2276
16th to endNight
19%7%35%43445%7%35%
1948
March1st to 15thNight
25%7%35%424346%32%
1980
16th to endNight
22%7%2432335%6%37%
2112
April1st to 15thNight
17%6%35%5%2345%7%37%
1814
16th to endNight
9%5%24323447%53%
1761
May1st to 15thNight
6%313323348%59%
1619
16th to endNight
6%6%25%323437%53%
1541
June1st to 15thNight
6%5%34323436%56%
1440
16th to endNight
421211223472%
1440
July1st to 15thNight
111112235%78%
1503
16th to endNight
1211222237%72%
1701
August1st to 15thNight
2313345%74%
1620
16th to endNight
2221123477%
1851
September1st to 15thNight
1311211235%76%
1800
16th to endNight
4323212446%63%
1850
October1st to 15thNight
9%5%14312235%60%
1980
16th to endNight
12%5%14424446%47%
2112
November1st to 15thNight
14%5%24335%5%6%7%39%
2170
16th to endNight
18%6%2442435%7%40%
2520
December1st to 15thNight
24%7%25%423336%36%
2520
16th to endNight
27%8%25%313335%33%
2688

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
48%5%9%15%11%9%
1566
16th to endDay
47%36%12%15%13%
1728
February1st to 15thDay
48%47%16%18%4
1576
16th to endDay
50%6%11%19%8%2
1523
March1st to 15thDay
55%5%9%12%14%2
1980
16th to endDay
51%5%12%16%10%2
2112
April1st to 15thDay
49%6%12%22%9%
2133
16th to endDay
34%5%14%26%14%4
2197
May1st to 15thDay
25%5%12%32%17%5%
2331
16th to endDay
32%6%11%33%13%2
2573
June1st to 15thDay
29%5%11%21%23%8%
2520
16th to endDay
16%36%22%37%12%
2520
July1st to 15thDay
9%26%16%36%28%
2310
16th to endDay
10%27%10%30%38%
2313
August1st to 15thDay
10%28%21%32%24%
2324
16th to endDay
10%29%19%34%23%
2351
September1st to 15thDay
11%28%17%32%27%
2160
16th to endDay
16%28%24%29%19%
1810
October1st to 15thDay
27%47%23%24%12%
1650
16th to endDay
32%5%9%23%19%9%
1760
November1st to 15thDay
40%5%13%23%9%8%
1684
16th to endDay
43%6%10%15%18%5%
1440
December1st to 15thDay
48%5%9%16%15%4
1440
16th to endDay
53%5%8%13%14%4
1536
January1st to 15thNight
48%7%10%13%12%8%
2370
16th to endNight
45%5%6%15%14%12%
2496
February1st to 15thNight
50%5%9%15%14%5%
2288
16th to endNight
48%6%11%19%11%2
1948
March1st to 15thNight
53%5%11%13%13%2
1980
16th to endNight
47%415%18%11%2
2112
April1st to 15thNight
45%6%15%19%11%1
1814
16th to endNight
30%415%29%16%3
1761
May1st to 15thNight
23%7%9%29%23%6%
1620
16th to endNight
30%7%9%33%14%4
1542
June1st to 15thNight
28%7%12%20%22%8%
1440
16th to endNight
15%27%22%36%15%
1440
July1st to 15thNight
8%2416%37%30%
1418
16th to endNight
11%210%7%28%39%
1593
August1st to 15thNight
10%39%19%28%27%
1611
16th to endNight
10%39%18%31%27%
1851
September1st to 15thNight
11%17%15%34%29%
1800
16th to endNight
19%39%21%26%19%
1850
October1st to 15thNight
26%38%22%25%13%
1980
16th to endNight
36%49%19%20%9%
2112
November1st to 15thNight
41%7%16%17%10%6%
2170
16th to endNight
42%5%11%18%16%5%
2520
December1st to 15thNight
50%49%16%15%4
2520
16th to endNight
53%48%13%14%5%
2688

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
36%10%16%21%12%2
195
16th to endDay
32%8%18%21%13%5%
256
February1st to 15thDay
29%11%23%22%12%
236
16th to endDay
28%16%23%20%9%1
225
March1st to 15thDay
39%11%27%14%5%2
270
16th to endDay
29%21%28%14%41
288
April1st to 15thDay
28%19%30%13%5%2
269
16th to endDay
24%23%25%19%42
270
May1st to 15thDay
16%21%30%21%6%3
288
16th to endDay
17%14%26%22%13%6%
330
June1st to 15thDay
14%12%33%28%6%3
315
16th to endDay
6%9%33%35%9%4
315
July1st to 15thDay
3420%46%18%6%
305
16th to endDay
2221%47%17%8%
327
August1st to 15thDay
2329%40%17%6%
315
16th to endDay
1325%42%18%8%
332
September1st to 15thDay
5%5%21%42%16%8%
315
16th to endDay
8%6%25%34%16%8%
260
October1st to 15thDay
15%10%26%25%15%7%
255
16th to endDay
19%11%25%26%15%1
272
November1st to 15thDay
15%12%18%25%23%5%
208
16th to endDay
16%11%38%18%10%5%
60
December1st to 15thDay
48%8%21%16%31
60
16th to endDay
25%10%14%21%17%10%
64
January1st to 15thNight
23%312%30%24%6%
720
16th to endNight
25%310%26%25%8%
768
February1st to 15thNight
25%412%28%23%5%
704
16th to endNight
23%5%19%28%18%5%
632
March1st to 15thNight
30%5%10%27%21%5%
720
16th to endNight
26%7%14%27%19%3
768
April1st to 15thNight
21%8%18%26%19%5%
719
16th to endNight
12%8%17%29%25%6%
681
May1st to 15thNight
7%319%29%32%7%
540
16th to endNight
9%417%29%31%7%
420
June1st to 15thNight
8%5%19%32%31%3
360
16th to endNight
4111%40%36%5%
360
July1st to 15thNight
26%24%52%15%
398
16th to endNight
3421%50%20%
564
August1st to 15thNight
1321%54%18%
538
16th to endNight
3424%49%16%
705
September1st to 15thNight
317%23%46%18%
720
16th to endNight
6%39%27%34%17%
664
October1st to 15thNight
12%310%30%29%13%
660
16th to endNight
16%39%22%34%14%
704
November1st to 15thNight
18%214%28%28%8%
700
16th to endNight
21%410%30%25%8%
720
December1st to 15thNight
29%411%27%19%8%
720
16th to endNight
29%5%17%24%17%4
768
Page generated at 2017-09-18 05:38:27. Version ac04

Copyright 2017 A. Danko


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