Poles uneasily remember their heady August of 1980

August is closing in a wave of glorious sunshine here. But uppermost in most Polish minds are the even sunnier days at the end of August 1980. Those were the days of the historic agreements that ended more than two weeks of strikes at Poland's Baltic ports, first at Szczecin Aug. 30 and at Gdansk the next day. Early in September a third agreement was reached between the communist authorities and the miners in the south.

These three accords produced:

* The first independent labor union movement in the communist world.

* A range of concessions from communist rulers and ruled going well beyond the short-lived gains of the periodic reform movements that mushroomed up in Eastern Europe between the 1950s and the '70s.

* A euphoric belief that this time things would be different in Poland and that the hopes of lasting reform would not be dashed as they had been twice before.

Within 16 months the union was outlawed and, during a year of martial law, formally liquidated. Most of the other gains have been severely curtailed, and euphoria and hope replaced with a mood of public resignation.

Over the past few weeks there has been a sharp argument between the authorities and the last vocal elements of a rearguard Solidarity underground as to how and why it all happened the way it did.

The Jaruzelski government is trying to impress public opinion with its own continued commitment to the essence of the August reforms; that many of them have been carried through; and that where they have been cut back, it was because of the union, which launched out on political platforms that had no place in the promised ''renewal'' program but were aimed at the overthrow of the system itself.

The government has just issued a pamphlet entitled, ''August agreements: hope , reality, and perspective,'' that seeks to convince readers that it has honored the spirit of the August accords. It calls for ''honest (public) assessment'' and a ''responsible civic'' pondering of why things went so badly wrong.

It is difficult to tell whether this effort is having any effect. Ordinary people seem not to be moved one way or another.

''We're hanging in some sort of vacuum in between,'' an intelligent younger Pole remarked to this writer. ''It is a case of not knowing where to put your hopes. And without that it is difficult to find an anchor for your effort and activity.''

The basic question for the government still seems to be its ability to establish credibility with its own rank and file as well as to awaken interest and care in opinion at large.

As they did in the months leading up to the imposition of martial law in December 1981, each side is accusing the other of dodging and breaking the agreements.

But until last week's dramatic meeting in the Lenin shipyard, which Vice-Premier Mieczyslaw Rakowski attended, Solidarity had no hearing.

That meeting was noteworthy because Lech Walesa, whom the authorities seek to make an ''un-person,'' was able to stand up and reply to the standard official charges that Solidarity and the political opposition had exploited the August agreements to mask ''antisocialist'' objectives.

Walesa spoke of the frequent official obstacles Solidarity had to contend with in the implementation period. ''Solidarity made its errors,'' he admitted, ''but the mistakes made by the authorities were even greater.''

He recalled that Solidarity was never ''a favorite child.'' Even ''liberal'' members of the regime had never found such a forthright labor organization a predictable or comfortable ''partner.''

''From the start,'' Walesa continued, ''the union had logs thrown at its feet - it had to fight for everything.''

The news media treatment of the Gdansk meeting reflected the authorities' continued ambivalence on the subject of Solidarity's former chairman. That evening television carried clips of the meeting, although such occasions involving a member of the government are usually given full treatment. Nonetheless, Walesa was seen on Polish TV screens for the first time since martial law was declared.

Over the weekend there was apparently some further thinking. Monday evening television presented a three-hour film of the encounter. Despite some evident editing, it was revealing enough of what went on.

The majority of the 700 to 800 workers present listened silently but intently to Rakowski's hecklers. They gave no sign that they were impressed by the vice-premier's arguments. The camera roved over faces that were reflective, unconvinced, sometimes openly ironic. None could be read as approving.