Can we get around the country without a tour and renting a car?
Depends. We didn't need a car in Edinburgh or getting from Edinburgh to Glasgow/Milingavie or Fort William. Local transit and coach/train between towns worked well. A car in Edinburgh in my opinion is more of a handicap than convenience.
...we want to know what to expect with weather....
You will be prepared if you expect anything but the mean. Mean Edinburgh air temperatures may sound mild with a mean high of +7C and mean low of +1C, but extreme temperature range from a +15C high to below -10C in the December-January season.
This region includes the cities of Edinburgh, Dundee and Aberdeen. The
principal geographic features comprise the valleys and estuaries of
the eastward-flowing Rivers Tweed, Forth, Tay and Dee and extensive
upland areas including the Grampian Mountains in the northern part of
the region and the Lammermuir Hills south of Edinburgh (rising to 500
metres above sea level). The highest point is Ben Macdui (1309 metres)
near the border of Grampian with Highland.
January is the coldest month, with mean daily minimum temperatures
varying from about 2 °C in areas of East Lothian and Fife bordering
the Firth of Forth and on the NE coast of Grampian, to less than -2 °C
over the higher ground. Extreme minimum temperatures usually occur in
January or February. Examples include the UK record low temperature of
-27.2 °C at Braemar (Grampian) on 10 January 1982 (a record shared with Altnaharra, Highland). This occurred during a severe cold spell
across Scotland with some night minima below -15 °C and day maxima
below -5 °C on several days. Conversely, to the lee of high ground
temperatures can occasionally reach up to 15 °C in winter when a south
or SW airstream warms up after crossing upland - an effect known as a
The number of hours of bright sunshine is controlled by the length of
day and by cloudiness. In general, December is the dullest month and
May or June the sunniest.
Eastern Scotland includes the sunniest places in Scotland, these being
on the coast of Fife where the average is about 1500 hours per year.
Other coastal places, for example in East Lothian, average more than
1400 hours but sunshine averages are lower elsewhere, and are lowest
over the Grampian mountains (less than 1100 hours).
Rainfall tends to be associated with Atlantic depressions or with
convection. The Atlantic Lows are more vigorous in autumn and early
winter and bring most of the rain that falls in these seasons.
Rainfall is generally well-distributed throughout the year. The
frequency of Atlantic depressions is normally greatest during the
autumn and winter but, unlike other parts of the UK, Scotland tends to
remain under their influence for much of the summer too. The wettest
months tend to be in autumn and early winter, whereas late winter and
spring is normally the driest part of the year.
Over most of the area, snowfall is normally confined to the months
from November to April, but upland areas often have brief falls in
October and May. Snow rarely lies at lower levels outside of the
period November to April.